What are the sampling methods for nucleic acid detection? (What are the sampling methods for nucleic acid detection? )

When taking the throat swab, the patient gargles with clear water, then asks the patient to open his mouth and make an "ah" sound, and uses a tongue depressor if necessary. Take out the sterilized cotton swab and gently and quickly wipe the lateral pharyngeal wall and posterior pharyngeal wall several times. The first method of nucleic acid detection is often to use throat swab, take patient's throat swab for PCR detection, gene amplification, and then detect nucleic acid. This specificity and sensitivity are relatively high. At present, we mainly use this method in clinic.

Serum detection

Antibody detection usually adopts the method of blood drawing, and the result of blood drawing depends on whether the antibody titer increases or not. This situation often means that patients often cannot produce antibodies in the early stage, so it is of little significance to detect patients in the early stage. Whether some cases have been infected with this kind of cardiovascular pneumonia, including the evaluation of patients' rehabilitation, is still of comparative significance, and it is also of certain significance to the screening of some people.

"Specimens of nasal secretions

When sampling the nasal swab, insert the swab vertically into the nostril until the finger is close to the nose, let the swab stay in the nose for 15-30 seconds, and then gently rotate it for 3 times.

Anal swab

Anal swab detection is to insert a sampling cotton swab into the anus for sampling 2 to 3 cm, or wipe the sample at the folds around the anus. Anal swab tests have been used to screen for parasitic infections. If you eat unsanitary food at ordinary times, the parasites in the intestine will lay eggs and be excreted with the stool. At this time, it is possible to find parasites through stool examination or anal swab. Because there are reports that a few discharged patients have an "unusual" situation, the throat swab is negative for nucleic acid twice, but the anal swab is positive. Therefore, anal swab test can also improve the detection rate of COVID-19 infected people to some extent.