Tag Archives: Rapid Antigen Nasal Saliva Test

Sample collection swab :How much do you know about nucleic acid testing

Sample collection swab :How much do you know about nucleic acid testing

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Sample collection swab:How much do you know about nucleic acid testing

The spread of the covid-19  is continuing worldwide. Although the global scientific and medical circles are making every effort to fight the epidemic, it is difficult to predict how the epidemic will develop in the future, and its impact on social development has appeared in many aspects.

Currently, COVID-19 cases are over 220 million.

Currently, COVID-19 cases are over 220 million.

In order to fully control covid-19, the general screening of local areas shall be carried out if necessary.

After identifying the detection object, how to detect it?

1、 What specimen to choose?

According to the recommendations of the American infectious diseases association, the following specimens were used:

The sensitivity of simple oropharyngeal swab may not be enough, so it is relatively easy to miss diagnosis.

The sensitivity of alveolar lavage fluid is the highest, but it is obviously not suitable for universal screening.

Nasopharynx swabs and other operations should also be standardized.

Improper operation may make the quality of collected samples not high, thus increasing the risk of missed diagnosis.

2、 Select the time of detection

It is very important for COVID-19 to measure RNA and choose the right time. One analysis included 7 studies, including 2 unpublished reports, to evaluate the detection efficiency of RT-PCR at different time points after exposure to virus :

On the day of exposure to the virus, the possibility of detecting viral RNA is almost zero;

On the fifth day after exposure, that is, the first day after infection, the detection probability was 62%

About the 8th day after exposure, i.e. the 4th day after infection, the probability of detection was 80%

On the 21st day after exposure, i.e. the 17th day after infection, the detection probability was 34%

In conclusion, exposure to COVID-19 may require multiple tests to avoid missed diagnosis. However, it is not recommended to repeat the test within 24 hours of the previous test; The interval between two tests shall be at least 24 hours.

After 28 days of exposure to the virus, if the infection has not been diagnosed, it is not necessary to continue the detection; At this time, it is almost certain that it is not infected.

Nucleic acid detection throat swab  sampling process

The COVID-19 nucleic acid was novel coronavirus, which was collected from sputum or lower respiratory tract by real-time fluorescent RT-PCR. If positive, the new coronavirus could be diagnosed. This is the basis for the diagnosis of new type of pneumonia. In addition to detecting the nucleic acid of the virus, it can also detect whether the virus in the specimen is highly homologous with New Coronavirus. If so, it can be diagnosed as New Coronavirus pneumonia. The virus is highly infectious and has the characteristics of human to human transmission, but the virus is sensitive to temperature and sunlight and ultraviolet rays.

Sample collection, nasopharyngeal swab sampling

Sample collection, nasopharyngeal swab sampling

Sample collection, Oropharyngeal swab sampling

Sample collection, Oropharyngeal swab sampling

The flocked swab is the best raw material for sampling swabs.

 

 

reference

1，Infectious Diseases Society of America Guidelines on the Diagnosis of COVID-19, updated December 23, 2020. https://www.idsociety.org/practice-guideline/covid-19-guideline-diagnostics/ (Accessed on January 14, 2021).

2，Kucirka LM, Lauer SA, Laeyendecker O, et al. Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction-Based SARS-CoV-2 Tests by Time Since Exposure. Ann Intern Med 2020; 173:262.

 

Nasal swab pcr test

Nasal swab pcr test

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Nasal swab pcr test COVID-19 Antigen Rapid Test Kit

Detection of COVID-19 by nasal swab PCR is an accurate and reliable method. Positive detection means you may have SARS-CoV-2. Negative detection means you may not have SARS-CoV-2 when testing.

In order to ensure your safety, if you have symptoms of COVID-19. Or people who have been exposed to the virus and tested positive should be tested.

What is the symptom of COVID-19?

If you have the following symptoms,if you have the following symptoms, please buy covid-19 antigen rapid test kit immediately or go to a nearby hospital for PCR test.

1.Fever;

2.General fatigue;

3.cough;

4.Dyspnea or even respiratory failure；

5.Nausea;

6.vomiting;

7.abdominal pain;

8.diarrhea;

Symptoms of New Coronavirus pneumonia are not necessarily typical, and some patients may not have clinical manifestations at the early stage of New Coronavirus infection. Then clinical manifestations will appear, that is, “asymptomatic infection” in incubation period.

In other words, try to avoid activities in places with crowd gathering, closed space and poor ventilation.

What is nasal swab PCR test？

Polymerase chain reaction (PCR) uses a piece of DNA as a template. Then, with the participation of DNA polymerase and nucleotide substrate, the DNA was amplified to a sufficient number for structural and functional analysis.

Scientists use PCR technology to amplify a small amount of RNA in the sample into deoxyribonucleic acid (DNA) and replicate until COVID-19(if present) is detected.

What should we pay attention to before doing nucleic acid test？

1.Try not to eat 2 hours before sampling to avoid vomiting.

2. Do not smoke, drink, drink water or chew gum 30 minutes before sampling.

3. The tester needs to wear a mask correctly and remove the mask before testing;

4. Wear it immediately after testing, and prepare a spare mask for easy replacement at any time after pollution.

5.When you feel sour and itchy in your nose or sneeze, you can immediately cover it with a paper towel or elbow.

Before collecting nasopharyngeal swabs and before being tested, the collection personnel shall be informed whether they have relevant past medical history. For example, history of nasal surgery, history of deviation of nasal septum, blood diseases, throat diseases, etc

How long will we know the pcr test results？

The test results of sampling in the morning are generally available from 18:00 to 19:00.

The detection results of afternoon sampling can generally be queried around 22:00.

What’s the difference between the PCR and antigen tests for COVID-19?

Polymerase chain reaction (PCR): PCR is the most reliable and accurate method to detect active infection. PCR tests usually give results in a few hours.

Antigen detection: detect protein fragments on the surface of covid-19. Antigen detection usually takes only 15 to 30 minutes.

How can we prevent COVID-19?

Firstly, keep good personal hygiene habits, wear masks when going out, wash hands frequently, clean the room, and wipe the floor and other furniture with disinfectant. Second, disinfect your hands with 75% alcohol every time you go out and go home, reduce the number of times you go out, and wear qualified masks. And the diet should also be light, do a good job of physical exercise and enhance personal physique.

Most importantly, if our conditions permit, we should vaccinate and conduct multiple nucleic acid tests.

If our Nasal swab pcr test results are positive,what should we do?

If our test results are positive, don’t be afraid. We should wear masks and go to the nearby Hospital for follow-up in time.

Repeat the nucleic acid test.Don’t be afraid and hide the test results. Timely medical treatment is the best choice.

Cell medical (Dongguan) Co., Ltd. is a comprehensive high-tech biotechnology company and an OEM factory of flocking swabs in China.We support custom production,our factory produces flocked swabs, pharyngeal swabs, nasal swabs, oral swabs,Rapid Antigen Test Kit, virus sampling tubes, transportation media, sample preservation solution and nucleic acid extraction kit.

Welcome to leave a message and consult us!

 

 

New Coronavirus nucleic acid detection

New Coronavirus nucleic acid detection steps

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New Coronavirus nucleic acid detection steps

1、 The specific operations are as follows

1. Virus sampling:

Take the patient’s saliva sample or nasopharyngeal flocked swab sample, and save the virus sampling tube.Virus preservation solutions commonly used in disposable virus tubes include inactivated and non inactivated types. The following are two models of virus transport medium:

1) Inactivated type: the inactivated virus transport medium characterized by killing the virus and retaining nucleic acid fragments. Application:detect COVID-19, influenza virus, hfmv and influenza A.

2) Non inactivated type: the non inactivated virus transport medium does not contain lysate. It can retain the activity and integrity of pathogens.Application:virus culture and reproduction to make the detection results more accurate.

flocked swab specimen collection_New Coronavirus nucleic acid detection steps

flocked swab specimen collection_New Coronavirus nucleic acid detection steps

2. Nucleic acid extraction:

Extract the genetic material from the patient’s sleeping fluid or nasopharyngeal swab sample. If a patient carries a virus, there will be RNA of the virus’s genetic material in the sample. Sampling personnel should pay attention to prevent RNA degradation when extracting RNA. At the same time, the extracted DNA shall be stored at – 20 ℃, and the RNA and DNA requiring long-term storage shall be stored at – 70 ℃ or liquid nitrogen.

3. Reverse transcription synthesis of cDNA:

reverse transcription of RNA in the extract, reverse transcription of RNA into cDNA, reverse transcription of cDNA synthesis reaction, using reverse transcription primers, dNTPs, reverse transcriptase, RNase inhibitor and DTT. Buffer, an appropriate amount of ultrapure water without RNA / DNase and RNA template. We propose to use commercially available RT-PCR one-step reagent for one round amplification of di.

4. PCR amplification reaction (nested PCR amplification method with secondary amplification):

Use specific primers of virus cDNA for PCR amplification in an amplification instrument. Nested PCR amplification using secondary amplification.

5. Result analysis and judgment:

If the DNA band of the virus is amplified, it is determined that the virus exists in the patient; If no DNA band is amplified, it is determined that the sample taken by the disease has no virus.

2、 Experimental precautions:

① We should set up two positive controls and two negative controls for each test. Only when the positive control enlarges the expected fragment, the negative control does not enlarge any fragment, and the results of two parallel samples are consistent.We can determine the nucleic acid positive or negative reaction results.

② Nucleic acid test is positive: if nucleic acid is positive, we should repeatedly collect samples for retest. If the retest result is nucleic acid positive, we can confirm that the sample result is nucleic acid positive. If the retest result is nucleic acid negative, the nucleic acid test result is uncertain.

Nasopharyngeal swab rapid test

Nasopharyngeal swab rapid test_Individual Package Self Test At Home

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Rapid Antigen Test Kits for COVID-19

Individual Package Self Test At Home POCT Lateral Flow Antigen Bfarm 19 Nasopharyngeal Swab Saliva Antigen Rapid Test Kit

Individual Package Self Test At Home POCT Lateral Flow Antigen Bfarm 19 Nasopharyngeal Swab Saliva Antigen Rapid Test Kit

 

Specimen types
 Nasopharyngeal swab/oropharyngeal swab
Testing time
10 minutes
Sensitivity
96.15%
Specificity
99.78%
Accuracy
99.09%
Packaging
 1 Sets/Box
Certificate CE/ISO13485/TGA
Place of origin
Dongguan,China
Port
Shenzhen,China
Nasopharyngeal swab collection method

Nasopharyngeal swab collection method

Collection method of Oropharyngeal Sampling Swab

Collection method of Oropharyngeal Sampling Swab

sample preparation,test procedure & interpretation of results

sample preparation,test procedure & interpretation of results