According to the Notice of the General Office of the National Health and Wellness Commission on the requirements for medical institutions to conduct nucleic acid testing for the new coronavirus (National Health Force, Medical Letter (2020) No. 53) and the relevant requirements of the New Coronavirus Laboratory Biosafety Playbook (Second Edition), sampling and laboratory testing personnel should use personal protection at the biosafety level 3 laboratory level. After completion of testing operations, waste is disposed of strictly in accordance with the documented requirements, and samples in virus sampling tubes should not be preserved. This paper uses pharyngeal swabs as an example of operation, the specific operation process is as follows.

I. Material preparation

1. Virus sampling tube. Conventional sampling tube, the recommended standard disposable virus sampling tube containing 1-2mL of virus preservation fluid.

2. Pharyngeal swab

3. Oscillator.

4. Other customary materials for nucleic acid detection preparation

II. Sampling and mixing

1. Pharyngeal swab sampling method. The head of the collected person is slightly tilted, the sampler will jump the swab over the tongue root, wipe slightly back and forth in the pharyngeal tonsils on both sides of the collector at least 3 times, dip the swab head into the tube containing 1-3mL of virus preservation solution, discard the tail, screw the cap.

2. Sample mixing. Take 200uL of each of several samples collected (in principle, no more than 5) to mix adequately and constitute a mixed sample to be picked up.

Three, nucleic acid detection

Nucleic acid extraction and detection process according to the standard operating procedures of the relevant laboratory practices. In each sample amplification, 80 spiked wells are used for mixed samples (such as 5 mixed 1, a total of 80*5 single samples); 10 spiked wells are used for single samples (single samples from the above 80*5 random samples of the original solution).

IV. Positive results judgment and retest

1. The test results are first determined in accordance with the requirements of the test kit instructions, the genetic loci are tested one by one, presenting either a positive locus or a mixed sample of Ct value can be measured, are used as a retest target.

2. If the Ct value is detected in the mixed sample, all the individual samples of the original solution should be sampled from scratch and single sample nucleic acid testing should be performed according to the usual method.

3. single sample detected positive, the mixed samples in which all the samples should be single sample nucleic acid testing according to the usual method.