Sampling with disposable virus sampling tube is mainly divided into oropharyngeal sampling and nasopharyngeal sampling:
1. oropharyngeal sampling: first press the tongue with a tongue depressor, then extend the head of the sampling swab into the throat, wipe the bilateral pharyngeal tonsils and the posterior pharyngeal wall, and gently wipe the posterior pharyngeal wall with force so as not to touch the tongue.
Disposable virus sampling tube
2. Nasopharyngeal sampling: Measure the distance from the tip of the nose to the earlobe with a cotton swab and mark it with your finger. Insert the swab into the nasal cavity along the direction perpendicular to the nose (face). The swab should reach at least half of the length from the earlobe to the tip of the nose so that the swab stays in the nose for 15-30 seconds, rotate it gently 3-5 times, and then remove the swab.
It is easy to see from the method used that sampling is a technical activity that is difficult and prone to contamination, and the quality of the collected sample is directly related to the subsequent testing.
If the collected sample has a low viral load, it is easy to cause a false negative and it is difficult to make a diagnosis.
Currently, most of the samples recommended by the kits sold in the market are oropharyngeal swabs or nasopharyngeal swabs and alveolar lavage fluid.
The work of the sampler can be greatly reduced if blood is collected using venous blood samples, especially special nucleic acid test tubes, to extract and purify RNA for testing. After all, collecting a venous blood sample is not difficult, just like testing for hepatitis C ribonucleic acid. 5 ml of ethylenediaminetetraacetic acid anticoagulated blood sample can separate the plasma and the extracted and purified ribonucleic acid is perfectly adequate for polymerase chain reaction testing.
