Pcr test nasal swab and an antigen test difference for covid 19

Posted on 2021年9月18日2022年3月22日 by Dr. Lee

What is COVID-19?COVID-19 is an epidemic disease caused by SARS-CoV-2. An acute respiratory infectious disease broke out at the end of 2019. So far, WHO has been making the latest tracking report on the new pneumonia on the Internet every day.

What are the current methods of COVID-19 test?

Virus detection includes two types: nucleic acid amplification test (NAAT) (PCR test) and antigen test.

Antibody tests (also known as serological tests) can prove whether you have been infected in the past.

What is the COVID-19 PCR test?

PCR (polymerase chain reaction): similar to the natural replication process of DNA, its specificity depends on oligonucleotide primers complementary to both ends of the target sequence.

Basic principle: the basic principle of PCR technology is similar to the natural replication process of DNA. Its specificity mainly depends on the oligonucleotide primers complementary to both ends of the target sequence. It consists of three basic reaction steps: denaturation, renaturation and extension.

PCR test sample collection method include:

If the sample contains a virus, the researchers will extract its RNA.

Why use the PCR test ?

PCR nucleic acid examination is a direct detection of COVID-19 RNA in human body by sampling from the nasal cavity. The structure of virus is composed of DNA or RNA combined with external lipid protective capsule. Therefore, direct detection of virus DNA itself is the most accurate, fastest and effective new detection method. PCR nucleic acid test can detect infection immediately after the human body obtains the virus, and the accuracy is much higher than antibody test.

ABOUT PCR TEST_Pcr test nasal or Throat swab sampling

How does the PCR test nasal swab work?

Nasopharynx swab is to wipe the secretion of the patient’s nasal cavity or pharynx. And then make the secretion into smear for examination and bacterial culture to clarify what bacterial infection is in the patient’s nasal cavity and pharynx.

Nasal swab sampling procedure

1. Keep the patient’s head still and remove the secretions on the middle surface of the anterior nostril;

2. Gently and slowly insert the swab through the nasal cavity to the nasopharynx;

3. After encountering resistance, it reaches the posterior nasopharynx and stays for several seconds to absorb secretions;

4. Gently rotate and take out the swab and place it in the transport medium;

5. For the swab used for virological test, immerse the swab head into the virus delivery medium, discard the tail, and tighten the tube cover;

If it is necessary to collect from both nostrils, the sampler should use the same swab.

How does the antigen test work?

Rapid antigen detection can play an important role in guiding patient management, public health prevention and control decision-making and covid-19 monitoring.

It is especially valuable for grass-roots areas that may hinder clinical diagnosis and control due to lack of nucleic acid detection capacity or long detection time.

According to WHO, high specificity based on antigen detection indicates that the positive results indicate new crown virus infection.

For patients within 9 days of onset, sampling personnel can use antigen detection as a diagnostic test.

Especially for the staff of medical institutions, inpatients and visitors in the epidemic area.

When nucleic acid detection cannot be effectively implemented, antigen detection can be used as an important screening method.

Rapid antigen test sampling procedure.

Rapid antigen test sampling process

Generally speaking, nucleic acid detection: it has high requirements for laboratory environment, detection personnel and instruments. The detection has high sensitivity and good specificity.Generally, we can get the results in 2-3 hours.

Antigen detection: it has low requirements for the laboratory. For early screening and early diagnosis. It is suitable for large-scale screening in grass-roots hospitals. we can obtain the results within 15 minutes at the fastest.

At present, PCR test nasal swab is widely used, and the sensitivity and specificity of antibody / antigen detection reagents are still limited.

Each has its own emphasis and cannot replace each other. We should combine multiple virus detection methods.

It can effectively shorten the detection window period and improve the positive detection rate.

COVID-19 Testing:PCR swab test,antibody test, and antigen test difference

Posted on 2021年9月17日2022年3月22日 by Dr. Lee

COVID-19 Testing :PCR swab test,antibody test, and antigen test difference.

PCR swab test（Nucleic acid test） and antibody / antigen detection are important means to confirm COVID-19, and also one of the important processes for patients to diagnose. But do you know what their detection principle is? What are the sample types? What is the inspection process and what are the problems?

COVID-19 nucleic acid test

Nucleic acid detection has the characteristics of early diagnosis, high sensitivity and specificity. At present, real-time fluorescence quantitative RT-PCR is the most widely used technology. PCR swab testing is a very effective way to identify SARS-COV-2.

1. Principle of COVID-19 test kits?

The researchers used sampling swabs to collect samples of the virus, targeting the unique gene sequence of the virus.

By PCR amplification of the virus sample, the target DNA sequence we selected increased exponentially.

Researchers can combine the amplified DNA sequence with pre added fluorescent labeled probe fragments to generate fluorescent signals.

The more target genes amplified, the stronger the cumulative fluorescence signal.

In Virus-free samples, no target gene was amplified. Therefore, researchers can not detect enhanced fluorescence signals.

That is, we do not carry COVID-19.

Therefore, nucleic acid detection is actually to detect the accumulation of fluorescence signal to determine whether there is viral nucleic acid in the sample.

COVID-19 test kits_PCR swab test（Nucleic acid test）

2. What are the methods of covid-19 testing samples?

Generally, PCR nasal swab test, pharyngeal swab, nasopharyngeal swab, sputum, bronchial lavage fluid, alveolar lavage fluid, etc.

Sampling swab consists of a nylon flocked swab.what is a flocked swab?

3. Steps of PCR swab test for COVID-19.

At present, pharyngeal swabs are the main sampling method for the diagnosis of novel coronavirus infection. Correct sampling is the key to improve the accuracy of nucleic acid samples collected from pharyngeal swabs. What are the factors affecting the accuracy of nucleic acid samples collected from pharyngeal swabs? There are three main aspects:

Depth of throat swab collection?

How long is the throat swab in contact with the mucosa?

Pharyngeal swab sampling “dot to dot” or wipe?

(1) Oral and pharyngeal swab collection tips

1. Sampling position: sit or semi-sit in decuffine position, with head slightly raised and mouth open, and head resting on the wall or against the back of the chair.

2. Standard sampling operation: Sampling personnel press the tongue of the subject with tongue depressors.

Pharyngeal swabs should be performed on both sides of the pharyngeal tonsil with “Quick wipe up and down” and on the posterior pharyngeal wall with “Quick left and right wipe” . Repeat 3 to 4 times.

Avoid contact with tongue, teeth and gums.

If you feel uncomfortable, quit, take a break, and try again.

Oropharyngeal Sampling flocked swab diagram

3. Precautions: Drinking water before oral and pharyngeal swab test will dilute the virus attached to the pharynx, especially drinking hot water will inhibit the activity of the virus.

In order to improve the accuracy of pharyngeal swab nucleic acid detection, we recommend that subjects do not drink water 15-30 minutes before the detection, so as to ensure the high accuracy of pharyngeal swab nucleic acid test.

(2) Nasopharyngeal swab collection tips

1.The sampling personnel shall collect samples from the side of the subject, and the subject shall pull down the mask to expose only his nostrils. If there is sneezing reflex, the subject can cover it with elbow or paper towel.

nasopharyngeal sampling diagram

2. Standard sampling operation: “one insertion, two stops and three rotations” — measure the distance from the tip of the nose to the front of the ear, half of the insertion length, usually about 4 cm for adults; Stay for 15-30 seconds to absorb nasopharyngeal secretions (depending on tolerance, minimum stay for at least 3 seconds; Rotate the nasopharyngeal swab for 1 week and slowly remove it.

The above is for the reference of sampling medical staff and patients, let’s work together to defeat COVID-19!

(3)Store samples

Dip the flocked swab head into the cell preservation solution(Virus transport medium), and tighten the tube cap immediately after breaking the tail;

Storage, put the sample tube into a sealed bag for timely inspection, and the inspection process requires a strict transportation environment, 2-8 ℃ storage.

(4) PCR TEST

Researchers operate nucleic acid extraction, extract inactivated virus samples for subsequent nucleic acid detection, and can use automatic equipment such as nucleic acid extractor.

Fluorescence PCR nucleic acid detection, that is, on the machine detection, the extraction of fluorescence PCR amplification reaction, needs 70-80 minutes.

process pcr test

4. What are the problems in nucleic acid testing?

False negative, due to improper sampling, improper specimen preservation, the use of different types of specimens and the use of different manufacturers of reagents may lead to nucleic acid test results “false negative” and missed diagnosis;

■ High requirements for detection equipment or platform, high sensitivity RT-PCR instrument is expensive, laboratory cleanliness and operator requirements are also high;

■ Nucleic acid testing is time-consuming. It usually takes 4-6 hours to complete an RT-PCR test.

Therefore, when the nucleic acid test is negative.

Relevant personnel can increase the detection of IgM and IgG antibodies to make up for the shortcoming that nucleic acid detection is easy to cause missed diagnosis.

COVID-19 Testing serum antibody test

Seven days after novel coronavirus pneumonia, the serum specific antibodies gradually emerged. The first is immunoglobulin IgM antibody, and then IgG antibody.

Thus, an elevated IgM antibody indicates a recent acute infection, and an elevated IgG antibody indicates a previous infection.

The biggest advantage of serological testing lies in its convenience and short detection time, which can effectively break through the limitations of existing detection technology on personnel and sites and shorten the detection time.

Novel coronavirus infection can be diagnosed in suspected cases if the serum specific IgM and IgG antibodies are positive, the IgG antibody changes from negative to positive, or the recovery period increases by 4 times or more than the acute period.

antibody test sampling process_COVID-19 Testing

1. Principle of serum antibody test kit?

The sample is added to the sample adding hole, and the sample will move forward along the detection card under the action of chromatography.

If the sample contains new coronavirus IgM antibody, the antibody will combine with colloidal gold labeled virus antigen to form a sandwich complex, which will show a positive result.

If the sample contains New Coronavirus IgG antibody, the antibody will bind to colloidal gold labeled New Coronavirus antigen and form a sandwich complex, which will show positive results.

The detection card also contains a quality control line (line C) to judge whether the chromatography process is smooth.

2. What are the sample types for serum antibody detection?

Generally, it is blood, including serum, plasma and whole blood.

3.COVID-19 antibody test in three steps

1. Open the aluminum foil bag of the test card, take out the test card and place it horizontally on the table;

2. Use a pipette to absorb serum/plasma/whole blood sample and add it to the sampling site. Then use the same method to absorb buffer drops and add them to the sampling hole of the test card.

3. Wait 15 minutes and read the result.

4. What are the problems in serum antibody detection?

■ False positive, individual patients with rheumatoid factors in the blood, heterosinophilic antibodies, autoantibodies, drugs and tumor cells, etc., easy to cause cross-reaction test, so occasionally false positive results;

■ False negative, due to the existence of a certain window period of serum antibody detection methods and the sensitivity of the detection kit will appear false negative results.

Therefore, serum antibody test is only used as a supplementary test for suspected cases of novel Coronavirus nucleic acid negative test and cannot be used as a diagnostic indicator for screening alone.

The combined use of serum antibody detection and nucleic acid detection can help to improve the detection rate of the disease and find out the confirmed patients as much as possible, which is more conducive to the control of the epidemic.

Interpretation of results of nucleic acid combined with IgG and IgM antibody detection

COVID-19 Testing antigen detection

A novel coronavirus antigen test can novel coronavirus be detected directly in human body samples. The diagnosis is fast and accurate, with low requirements for equipment and personnel.

antigen test kit_SARS-CoV-2

1. Principle of antigen detection kit?

SARS-CoV-2 , N, E and S protein antigens stimulate virus cells to produce specific antibodies.

2. What are the types of antigen test samples?

Usually samples from infected sites, e.g. oropharyngeal swabs, nasopharyngeal swabs, sputum, serum, plasma, etc.

3.COVID-19 antigen test in four steps

1. Drop the sample treatment liquid into the sample treatment tube;

2. Stir the sample swab and squeeze the tube wall until the specimen is fully eluted into the treatment solution;

3. Take out the detection card and add sample to the round hole;

4. Wait 15 minutes and read the result.

4. What are the problems in antigen detection?

■ False negative, higher sensitivity of antigen detection is required. Because New Coronavirus mainly affects alveolar and other lower respiratory tract. Therefore, sampling from the upper respiratory tract of nasopharynx and oropharynx cannot determine whether the pathogen can be detected. Or the sample contains a small number of viruses. All these factors may cause missed detection.

■ The preparation process is tedious and time-consuming. The development of the antigen kit requires the preparation of the recombinant antigen first, and then the preparation of monoclonal antibody in mice, which takes about two or three months. If the prepared antibody performance is not good, it needs to be prepared again, which takes another two or three months.

The joint detection

The COVID-19 Testing nucleic acid / antibody / antigen has different focuses and can not be substituted for each other. Multiple detection methods are combined and complement each other. Combine molecular biology and immune level detection to give play to their respective advantages and improve sensitivity and specificity. It can effectively shorten the detection window period, improve the positive detection rate, and provide double guarantee for all possible risk groups.

reference：Zhengtu Li，Yongxiang Yi et al. Development and clinical application of a rapid IgM‐IgG combined antibody test for SARS‐CoV‐2 infection diagnosis. J Med Virol.2020；1-7

Mini flocked nose swab china factory and manufacturers

Posted on 2021年9月16日2021年12月21日 by Dr. Lee

Mini flocked nose swab china factory and manufacturersCell medical (Dongguan) Co., Ltd., flocked swab adopts vertical nylon fiber, which has stable and reliable performance and good adsorption and elution ability. Flocked swabs optimize sample collection and elution into the transmission medium. The swab also has a molded breakpoint that allows you to safely and easily disconnect the cotton swab. Our company provides multiple breakpoint options for different pipes.We can customize swab mold, swab packaging, sterile packaging and swab OEM services.

Mini flocked nose swab Specifications

Mini flocked nasal swab

Swab Length: 145mm±5mm
Flocked Tip Length: 8mm
Swab Tip Diameter: 8mm±0.2mm
Breakpoint: 80/90mm
Packing: Individual Sterile Package
Certificate: CE/FDA/ISO
OEM/ODM: Support
GMP Factory: YES
Supplying Ability: 500,0000pcs/ day

Application: Nasopharyngeal Sampling Swab

Mateiral: 100% Medical Grade Nylon

Sterilization: EO

Certificate: ISO13485, CE, FDA, SGS, MSDS, TDS.

What’s the use of a flocked nose swab？

Nasal swab detection is a kind of nucleic acid detection, which is used to detect the presence of viral nucleic acid in the body. So as to determine whether the human body infected with COVID-19.

Nasal swab detection requires collecting cells deep in the throat of the tested person and placing them in a Petri dish for observation. Because New Coronavirus is mainly transmitted through the respiratory tract,if the human body is infected with COVID-19, there will be a lot of viruses in the throat. Therefore, it is a more accurate way to detect the existence of COVID-19 by detecting the cells in the throat.

What is the method of mini nasal swab collection?

① Please keep the patient’s head still and remove the secretions on the surface of the anterior nostril;

② use a flocked swab or other tools to the distance from the nostril to the root of the ear and mark it with your fingers;

③ insert the swab gently and slowly through the nasal cavity;

④ swab until the finger mark or stay for several seconds after encountering resistance to absorb secretions; (generally stay for 15-30 seconds, and then rotate gently for 3 times);

⑤ gently rotate the swab and put it into the virus sampling tube (transport medium); Break the swab tail rod along the breaking point and place it completely in the tube. Tighten the pipe cover.

⑥ If you need to collect from two nostrils, you should use another swab.

⑦ Send to the inspection room for inspection as soon as possible.

⑧ Note the information of the collected person to avoid confusion.

Mini flocked nasal swab sampling display

Comparison of advantages of various testing methods of COVID-19

Posted on 2021年9月14日2021年9月15日 by Dr. Lee

advantages of various testing methods

The detection methods of COVID-19 mainly include nucleic acid detection, antibody detection and antigen detection. Due to the low detection rate of antigen, the SARS-CoV-2 detection mainly focuses on antibody and nucleic acid detection. Nucleic acid detection has the characteristics of early diagnosis, high sensitivity and specificity; However, antibody detection is convenient and rapid, which can be used as a supplementary means of nucleic acid diagnosis. Due to the limitations of “false positive” and “false negative” antibody detection, it is not suitable for general population screening such as returning to work, and school, nor for epidemiological investigation in low epidemic areas.

NAT Detection process

The detection procedure needs to go through five steps: sampling, sample retention, preservation, nucleic acid extraction and computer detection.

First, collect samples according to the instructions of the kit. The sample types include pharyngeal swab, nasal swab, sputum, bronchial lavage fluid, alveolar lavage fluid, etc.

Because RNA is easy to degrade, flocked swabs without RNase and storage tubes without RNase are used when collecting samples.

After obtaining the patient’s sample, it needs to be tested as soon as possible. If it cannot be tested immediately, it needs to be packaged at low temperature and sent to a special testing institution for testing.

After receiving the sample, the testing institution shall extract the nucleic acid from the sample. The nucleic acid extraction reagent shall use the nucleic acid extraction kit specified in the approved product manual.

Finally, fluorescence PCR nucleic acid detection, that is, machine detection. It takes 70-80 minutes to amplify the extract by fluorescence PCR.

Sample collection, oropharyngeal swab or nasopharyngeal swab

NAT Detection process Nucleic Acid Testing

Antibody detection

After the virus invades the human body, the human body will produce corresponding specific antibodies for defense.

According to different molecular structures and antigen specificity, scientists divide immunoglobulins into five categories: IgG, IgA, IgM, IgD and IgE.

After the antigen enters the human body for the first time, plasma cells secrete antibodies after a certain incubation period. IgM first appeared, but the antibody had short maintenance time, low concentration and low affinity. It lasted for several days to several weeks in the blood. It was a diagnostic index of acute infection; When IgM is about to disappear, the content of IgG reaches the peak. IgG appeared late, but its concentration was high, its maintenance time was long and its affinity was high. The positive serum IgG indicates the middle and late stage of infection or previous infection. But the antibody content increases rapidly in the short term, which may be several times to dozens of times higher than the original antibody content. It is mainly IgG, which lasts a long time in the body, and IgM rarely increases.

In this epidemic, the researchers studied patients with covid-19 and found that after the virus invades the human body, IgM antibody takes about 5-7 days to produce and IgG antibody takes 10-15 days to produce.

Antibody detection kits-advantages of various testing methods

Comparison of advantages and disadvantages of two different detection methods

Compared with the serological detection of antibodies, Nucleic Acid Testing can detect patients in the window stage.

Early detection of infected persons is the “gold standard” for COVID-19 detection, but it requires higher detection equipment or platform.

The high sensitivity RT-PCR instrument is expensive, and the laboratory cleanliness and operator requirements are higher. In addition, nucleic acid detection takes a long time. Considering the sample transportation and sample backlog, the results can be reported as soon as 24 hours.

Compared with nucleic acid detection, blood samples detected by antibody serology are easier to obtain. If the RNA of the virus detected by nucleic acid is the direct evidence of the existence of the virus, the antibody detection is the antibody stimulated in the patient’s blood, which is indirect evidence and has a suggestive effect on the clinic.

When nucleic acid detection is negative, adding IgM and IgG antibody detection can make up for the shortcoming that nucleic acid detection is easy to cause missed diagnosis.

About us

Cell medical (Dongguan) Co., Ltd., a professional VTM kits and swabs manufacturer, has many years of experience in medical application molding and flocked treatment heads and swabs.

Our flocked swabs are famous for their stable and reliable performance and excellent absorption and elution ability.Certificate:FDA,CE,EU,Free Sale,Export license based on (GMP).

We produce flocked swabs, VTM kits, Virus transport medium, with multiple automatic production lines.We support custom production, OEM and so on, and develop products with customers.

E-mail：flockedswabs@gmail.com
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Is anal swab nucleic acid test more accurate than nasopharyngeal swab?

Posted on 2021年9月13日2021年9月13日 by Dr. Lee

Is anal swab nucleic acid test more accurate than nasopharyngeal swab?

Nucleic acid detection:generally carried out by sampling pharyngeal swabs in the nasal cavity and oral cavity.

Now began to increase the anal swab test, we are also curious about this test method. So, is anal swab nucleic acid detection more accurate than nasopharyngeal swab? How to sample for anal swab test?

Is the nucleic acid detection of anal swab more accurate than that of nasopharyngeal swab?

In the screening of New Coronavirus pneumonia, we mainly used the oropharyngeal swab nucleic acid test. Because the reason is convenient and quick, suitable for large-scale screening. The accuracy of nasopharynx swab for new crown nucleic acid detection is higher than that of oropharyngeal swab, but the human body feels uncomfortable.

In last year’s test, researchers found that many infected people had negative pharyngeal nucleic acid.But their anal swabs were still positive for longer.

The combination of the two in nucleic acid detection can improve the detection rate and reduce the proportion of missed diagnosis.

However, anal swab sampling is inconvenient and not suitable for large-scale screening and testing in the community.

For some asymptomatic or mild infections, the condition recovers quickly after infection. And the pharyngeal nucleic acid may not be detected in 3 to 5 days.

The researchers found that the duration of nucleic acid positive in feces or anal swabs of some infected people was longer than that in the upper respiratory tract.

Therefore, increasing anal swab nucleic acid detection can improve the detection rate of infected patients and reduce missed diagnosis.

Although nucleic acid detection has the advantages of high sensitivity and short detection cycle, it also has some disadvantages.

Different from the direct isolation of live virus from human body, nucleic acid detection adopts an indirect method, which may cause false negative.

Anal swab & test tubes

How to sample for anal swab test

1. Soak the swab in normal saline, insert it into the anus of 2-3 cm, wipe it from the folds around the anus, or rotate it gently in the anus. And then insert it into the test tube containing normal saline.

2. For fecal swab culture, all the above operations require the use of sterile equipment and the swab into a sterile test tube.

Disposable virus sampler

Posted on 2021年9月11日2022年3月22日 by Dr. Lee

Disposable virus sampler

♦ Product Name:

① General name: disposable sampler

② Name: sample collection kit

③ Specification and model: cm-93050t, cm-93050rt, cm-93050rtz, cm-96000t, cm-96000ts, cm98000t, cm-98000tl, cm-761tz

♦ Package specification: 50 pcs / bag

♦ Intended use: disposable virus sampling tube_ Sampling swab_ Flocking swab_ Saliva collector_ Nucleic acid detection sampling kit_ Throat swab – cell medical (Dongguan) Co., Ltd.

Medical staff use DNA samplers and disposable samplers for sample collection, transportation and storage.

♦ Structure composition: swabs and test tubes. Non sterile.

Disposable virus sampler_cm-93050t

♦ Storage conditions and validity period:

① Products shall be stored in a clean, hygienic, dry and ventilated environment;

② . the temperature is 5 ℃ ~ 35 ℃;

③ . relative humidity ＜ 85% RH;

④ Product validity: two years

♦ usage method:

① Before sampling, relevant information shall be marked on the label of the sampling tube.

② . use the corresponding sampling flocked swab for sampling.

③ After sampling, quickly put the cotton swab into the sampling tube and tighten the tube cover.

④ . see the following for specific sampling methods:

a) Nasal swab: gently insert the sampling head into the nasopalatine part of the nasal canal, stay for a moment, then slowly rotate and exit, put the collected specimen into the sampling tube, and tighten the cover of the sampling tube.

b) Pharyngeal swab: wipe bilateral pharyngeal tonsils and posterior pharyngeal wall with the sampling head, put the collected samples into the sampling tube, and tighten the cover of the sampling tube.

c) Sampling of mycoplasma, chlamydia and Ureaplasma samples:

Male: insert the sampling head into the urethra and rotate about 2cm. Stay for a moment and then exit. Put the collected specimen into the sampling tube and tighten the cover of the sampling tube.

Female: wipe the mucus from the cervical mouth, insert the sampling head into the cervical tube for 1-2cm for sampling, put the collected sample into the sampling tube, and tighten the cover of the sampling tube.

♦ matters needing attention:

① . After collecting the sample, the medical staff shall completely insert the disposable sampling cotton swab into the test tube to retain the sample to the greatest extent.

② . the collected samples must be fresh and submitted for inspection in time.

③ .forbidden to use products with damaged packaging and expiration date to prevent pollution.

④ . forbidden to directly contact the collected patient, and forbidden to sample the patient after wetting the swab.

⑤ . When collecting samples, medical staff should strictly implement the sampling procedures to ensure that the sampling position is accurate and the sampling intensity is uniform and appropriate, otherwise the sample collection quality will be affected.

⑥ The product shall not be used after the expiration date or the product package is damaged.

Note: this disposable sampler : for in vitro diagnosis and not for human or animal internal and external use.

If swallowed, it may lead to serious events and cause certain irritation to eyes and skin. If it accidentally splashes into eyes, rinse with clean water.

♦ essential information

Name of manufacturer: cell medical (Dongguan) Co., Ltd

Domicile: No. 98, Wusha street, Chang’an Town, Dongguan City, Guangdong Province, China

E-mail： flockedswabs@gmail.com

What is genetic testing?

Posted on 2021年9月9日2021年9月9日 by Dr. Lee

What is genetic testing?

Definition of gene

What we usually call genes is a collection of genes in human cells, called the genome.

Every cell in our body has a complete genome. Inherited from parents and passed on to children.

Genes make people different from animals, make families different from families, and brothers and sisters are similar but different.

These subtle differences often do not exceed 0.5% of genes.

But determine different appearance, personality, genetic characteristics, and our adaptation to the external environment.

Why genetic testing?

It must be noted that various human traits and diseases are the result of the joint action of genes and environment .

Genes only play a partial role in traits, and whether gene expression is also greatly affected by the internal and external environment.

Therefore, gene test reports can not be directly used as the basis for clinical treatment, and it is not advisable to judge the role of genes without individual environment.

On this premise, the gene test report still has a certain reference significance for understanding various characteristics of the human body.

Understand that they carry hereditary pathogenic genes

We can know whether we carry pathogenic genes through genetic testing. For example, people with a family history of genetic diseases, cancer and hypertension. According to the test results, adjust dietary health care and living habits to avoid the occurrence of diseases. If both pregnant couples carry the pathogenic gene of recessive disease at the same time. They can pay attention and conduct further investigation when preparing for delivery.

Select drugs correctly to avoid drug waste and adverse drug reactions

Due to genetic differences, individuals will respond differently to drugs. When taking the same kind of drugs, some people will feel very effective, while others will not only be ineffective, but also have toxic and side effects. When some people use certain drugs, they may also have drug allergy. Through gene testing, we can know everyone’s gene situation, which may play a guiding role in drug use to a certain extent. Again, the drug test report can not be directly used in clinic. The drug selection and use in the treatment of diseases need to follow the doctor’s advice.

Provide scientific health management

Many adverse environmental factors and bad living habits will make the human body more prone to diseases. People can understand the occurrence tendency of individuals in different diseases through genetic testing, and make corresponding life adjustment or intervention in order to reduce the risk and delay the occurrence of diseases.

What is the principle of gene testing?

To understand the principle of gene detection, we need to understand the following questions:

Reasons for gene testing

Each person’s human nucleus has 23 pairs of chromosomes, which are composed of DNA and ribosomal proteins. All chromosomes have 3.16 billion base pairs.

When the same base pair position changes (this situation is generally called single nucleotide polymorphism, or SNP), which has a certain impact on human genetics and health, this SNP is the locus in the gene report. At present, there are nearly more than 100 million known or named SNPs. Most of the differences between human DNA are SNP differences, which is about 0.5% of the total base pairs of human DNA. A large part of gene detection is based on SNP.

Samples for genetic testing

Normal human samples required for gene testing include saliva sampling and blood sampling. For different examination items, excreta sampling and cell slice sampling are also included.

Methods of gene testing

There are several ways to measure related base pair differences (SNPs): PCR, chip, exon, and genome-wide. The number of SNPs detected is dozens, hundreds of thousands, tens of thousands, and all SNPs.

Disposable DNA sampling flocked swab

Oral DNA sampling swab_flocked swab cm-98000

1.Specially designed for micro DNA samples at the crime scene, especially for micro samples such as sweat, semen, blood, dandruff, oral cells, etc.

2. It can quickly absorb a small amount of samples and has high release aging rate.

3. The front end is sharp enough to extract cells from the victim or suspect’s fingernails.

4. The swab has a breakpoint, which is convenient for the automatic extraction workstation to extract samples.

5. The whole swab is packed in a transparent plastic tube to avoid biological pollution.

Who can do genetic testing?

① People with family disease history;

② People with bad living habits;

③ People exposed to chemical pollution, heavy metal pollution, nuclear pollution and toxic and harmful substances for a long time;

④ Friends who pay attention to health;

Hello!

When many diseases are diagnosed, it’s too late. Do a good job in disease prevention to make us healthy for a longer time!

COVID-19 Testing: Method of collecting virus swab samples

Posted on 2021年9月9日2021年9月17日 by Dr. Lee

COVID-19 Testing: virus swab

According to New Coronavirus’s pneumonia diagnosis and treatment plan (trial version fourth), to diagnose suspected cases of New Coronavirus pneumonia, we need one of the following etiological evidence:

1. Respiratory tract specimens or blood samples were detected by real-time fluorescence RT-PCR for New Coronavirus nucleic acid positive.

2. Novel coronavirus is highly homologous to respiratory tract specimens or blood samples.

Therefore, novel coronavirus pneumonia is an indispensable part of the specimen collection. So, where to collect specimens? How to collect specimens? How can medical staff protect themselves during collection? What should I do after collection?

How to obtain a virus swab specimen?

We all know that the collection method of virus swab specimen is basically to use the swab to sample the infected place or part of the virus, and then put it into the virus sampling tube containing preservation solution without touching other places, so as to conduct virus detection later.

Specimen type:

1. Upper respiratory tract specimens: including pharyngeal swab, nasal swab, nasopharyngeal extract, etc.

2. Lower respiratory tract specimens: including deep expectoration fluid, respiratory tract extract, bronchial lavage fluid, alveolar lavage fluid and lung tissue biopsy specimens.

3. Blood samples: try to collect anticoagulants in the acute stage within 7 days after onset. The collection volume is 5 ml, preferably fasting blood.

4. Serum samples: try to collect double serum in acute stage and recovery stage.

5. Conjunctival specimens: conjunctival swab specimens shall be collected for cases with ocular infection symptoms.

6. Stool samples: Patients with diarrhea symptoms need to collect stool samples.

COVID-19 Testing: Common virus swab sampling methods

Methods of throat swab collection

Inform the patient of the purpose of examination, collection method and collection time. It is best to collect specimens before using antibiotics.

Objective: To study the clinical effect of the method

Secretions were collected from pharynx or tonsil for bacterial culture or virus isolation to assist in clinical diagnosis and treatment.

Prepare sampling supplies:

Disposable sampling swab, virus sampling tube, tongue depressor and biological bag

Operation method:

(1) Ask the patient to sit down, tilt his head back, open his mouth and make a “ah ~” sound

(2) The sampling personnel shall fix the patient’s tongue with a tongue depressor, and use a disposable pharyngeal swab to pass through the root of the tongue to the posterior pharyngeal wall, tonsil recess and lateral wall;

(3) Repeatedly wipe 3-5 times to collect mucous membrane cells or sputum

(4) . gently remove the swab to avoid touching the tongue, the suspension, the oral mucosa and saliva

(5) Put the swab into the virus sampling tube gently and vertically. The sampling personnel shall disconnect the tail of the flocking swab and leave the tail of the swab completely in the tube.Be careful that the swab does not touch the wall of the tube.

(6) . tighten the cap, mark it, and seal it in the biosafety bag.

(7) The sampling personnel shall send the samples to the laboratory for testing in time. If the sampling personnel cannot send the samples for inspection in time, they shall store them at low temperature

Methods: nasal swabs were collected

Nasopharyngeal swab_COVID-19 Testing: Method of collecting virus swab samples

(1) Ask the patient to sit down with his head slightly back and remove the secretion from the front nostril first;

(2)measure the distance from nostril to ear base with swab and mark with finger

(3)gently insert the swab into the nostril until it is marked or stopped when there is obstruction. Let the swab stay in the nose for 15-30 seconds, and then rotate it gently three times.

(4) slowly pull out the nasal swab and quickly put it into the virus sampling tube. Then break the swab, leave its tail and place it completely in the tube.

(5) tighten the cap, mark it, and seal it in the biosafety bag.

(6) If we need to collect from both nostrils, we should use a swab.

(7) It should be sent to the laboratory for testing in time. If it can not be sent for inspection in time, it should be stored at low temperature.

Generally speaking, COVID-19 testing: the main methods of collecting virus swabs are nasopharyngeal sampling and oropharyngeal sampling.

Is COVID-19 pneumonia more infectious than SARS?

The effectiveness of infectious disease transmission depends on its basic regeneration index. Novel coronavirus pneumonia is more infectious than SARS at present, with a basic regeneration index of SARS higher than that of SARS.

The novel coronavirus pneumonia is a new disease, and the population is generally immune. Everyone is susceptible and susceptible to infection. The incubation period of COVID-19 also has the ability to transmit, and it has longer infection time. The novel coronavirus pneumonia novel coronavirus pneumonia is also typical of the clinical symptoms, and asymptomatic infections are also contagious, so the infection of new crown pneumonia is higher than SARS.

About us

Cell medical (Dongguan) Co., Ltd. is a swabs manufacturer. We produce and sell virus sampling related products. Such as virus sampling flocked swabs, VTM kits and virus transport media, and have multiple automatic production lines. We support customized production, OEM, etc., and develop products with customers.

Nasal swab for flu,Rapid antigen nasal or throat swab

Posted on 2021年9月8日2022年3月22日 by Dr. Lee

Nasal swab for flu_Rapid antigen (nasal or throat swab) test

Influenza is common in winter and spring. The clinical manifestations are mainly systemic poisoning symptoms such as high fever, fatigue, headache, cough and systemic muscle pain, while the respiratory symptoms are mild.

Influenza viruses are prone to mutation, infectious, susceptible to population and high incidence rate. They have caused many outbreaks in the world, and are important public health issues worldwide.

Why should we detect and prevent influenza?

According to the World Health Organization (WHO), seasonal influenza can cause 3-5 million severe cases and 290000-650000 deaths worldwide every year.

The researchers believe that children under the age of 5 are at high risk of severe influenza, but children under the age of 2 are at the highest risk, and infants under 6 months have the highest hospitalization rate and mortality.

Pregnant women, infants, the elderly, patients with chronic basic diseases and other high-risk groups have a higher risk of serious diseases and death after suffering from influenza.

Nasal swab for flu : common influenza test method

Nasopharyngeal sample collection

Influenza is an acute inflammation of the respiratory tract caused by the patient’s infection with influenza virus. The patient can have a series of symptoms such as cough, expectoration, fever, sore throat, stuffy nose, runny nose and general fatigue. In case of influenza, we should conduct relevant examinations in time to further clarify the diagnosis, including the following tests:

First, blood routine test, patients with influenza can promote the increase of lymphocytes. If combined with bacterial infection, there can be the increase of leukocytes and so on.

Second, scientists can culture throat swabs of influenza viruses. In throat swab culture, researchers can detect the related virus.

Third, influenza patients can do second-generation sequencing, including sputum second-generation sequencing, which can determine the type of virus infected.

Fourth, influenza patients can do the detection of respiratory pathogens to further clarify the pathogens of infection.

At present, the two most common influenza tests are rapid antigen diagnostic test and influenza virus cell culture test. Both tests rely on Nasopharyngeal swabs, pharyngeal swabs, etc. for virus sampling. The most commonly used sampling swab is nylon flocking swab.

Nasal swab for flu:Application

It is suitable for the detection and sampling of COVID-19, influenza virus , hand foot mouth disease virus, COVID-19, measles rubella and other types of viruses.

About nasal swab sampling

Why use flocked nylon swabs?

flocked swabs_Cell medical (Dongguan) Co., Ltd.

Flocked nylon swab: excellent sample collection / release ability, release rate > 90%.

Conventional fiber swab: the sample is intercepted by the gap in the fiber mass. That is, the sample is penetrated, diluted and intercepted in the fiber. Acquisition is slow and release is slower.

The sampling time of flocked swab is 3-5 seconds, while that of traditional swab is 15-120 seconds or even longer.

This caused pressure on the staff during the diagnosis process. Only by extracting samples faster can we complete the collection and analysis more efficiently.

Precautions for patients with nasopharyngeal swab:

① Please do not take antibiotics a few days before making nasal swabs;

② Do not use disinfectant mouthwash or smear the focus a few hours before nasal swab.

③ Do not eat, smoke or drink a few hours before doing nose swab.

Precautions for Sampler:

① . the sampler shall stand on the side of the patient for sampling.

② The patient is required to pull down the mask to expose only his nostrils. In case of sneezing reflex, the patient can cover it with elbows or paper towels.

If the sampler is not directly in front of the patient, the exposure risk will be lower.

③ If the patient’s turbinate is hypertrophic, the nasal tract is narrow, and the insertion of the nasal swab feels resistance. Try to change one side of the nasal cavity or directly change to oropharyngeal swab collection.

④ Those with nasal allergy symptoms are easy to induce sneezing. It is recommended to take oropharyngeal swab samples.

⑤ Remember to wear a protective mask / screen. For individuals who are highly suspected or basically diagnosed, or who have severe cough and hiccup, they should put on protective clothing.

⑥ After sampling, replace gloves, disinfect hands, and spray disinfectant where patients have touched.

Finally, we should pay attention to nasal swab for flu in special times. Remember to wear masks and personal hygiene when going out. Once you find the virus, please isolate it to avoid re transmission.

Unmanned nasopharyngeal swab sampling

Posted on 2021年9月6日2022年3月22日 by Dr. Lee

Unmanned nasopharyngeal swab sampling

Good news, at the China International Trade in services Fair on September 4.

the world’s first fully automatic nasopharyngeal swab sampling robot “Pengcheng Qinggeng” appeared at the service trade fair.

According to media reports, it can automatically grab and disinfect the cotton swab, and then use artificial intelligence to find the position of the face nasal cavity. The mechanical arm will put the flocked swab into the nostril, put it after the nostril, and then find the nasopharynx according to the force control, then rotate, sample and take it out, break the cotton swab and put it in the reagent box.

Unmanned nasopharyngeal swab sampling

Unmanned nasopharyngeal swab sampling marks the latest development of disposable specimen collection equipment. The main goal is to avoid this kind of contact infection of medical staff in high-risk applications.

At present, nasopharyngeal sampling swabs are mainly flocked swabs。

Cell medical (Dongguan) Co., Ltd. is a comprehensive high-tech biotechnology company and an OEM factory of flocking swabs in China.

We have many years of experience in medical application molding and flocking treatment heads and swabs. Our flocked swabs are famous for their stable and reliable performance and excellent absorption and elution ability.

flocked swab sampling

Our advantages

1.Efficient elution and sensitivity testin.

After experimental verification, the flocking swab proved that it can quickly elute > 95% of the original samples, and easily improve the detection sensitivity.

2.Ergonomic and anatomical design.

In order to improve the comfort of patients and the efficiency of cell sample collection.

3.Easy to collect, break, and then transport.

Open the package, collect the cell sample, and then break the broken point part of the swab into the delivery medium or the test tube provided.