There are several sampling methods for nucleic acid testing:
1. Nasal swab: the sampler gently holds the head of the person to be collected with one hand, and with one hand holds the swab against the nostrils to enter, and slowly goes deeper backward along the bottom of the lower nasal passage. When the tip of the swab reaches the posterior wall of the nasopharyngeal cavity, gently rotate it for a week, and then slowly remove the swab and immerse the head of the swab into a tube containing 2-3 ml of virus preservation solution.
2. Mouth swab: the head of the collected person is slightly tilted, mouth is opened wide, exposing both sides of the pharyngeal tonsils, the swab is passed over the root of the tongue, and the pharyngeal tonsils on both sides of the collected person are slightly rubbed back and forth with great force for at least 3 times, and then the posterior wall of the pharynx is wiped up and down for at least 3 times, and the head of the swab is immersed into the tube containing 2~3 ml of virus preservation solution, and the tail is discarded, and the cap of the tube is tightly screwed on.
3. Deep coughing of sputum: After the patient coughs deeply, collect the coughed-up sputum in a 50 ml screw-top plastic tube containing 3 ml of sampling solution.
4. Nasopharyngeal or respiratory tract extraction: Use the collector connected with negative pressure pump to extract mucus from nasopharynx or respiratory secretion from trachea.
5. Bronchial lavage fluid: Insert the head of the collector into the trachea (about 30cm deep) from the nostril or tracheal socket, inject 5ml of saline, turn on the negative pressure, rotate the head of the collector and withdraw it slowly. Collect the extracted mucus and rinse the collector once with the sampling fluid.
6. Alveolar lavage solution: after local anesthesia, insert the fiberoptic bronchoscope into the middle lobe of the right lung or the lingual segment of the left lung through the mouth or nose through the pharynx, fit its tip into the opening of the bronchial branch, and slowly add sterilized saline through the tracheal biopsy hole, 30-50 ml each time, with a total amount of 100-250 ml, which should not be more than 300 ml.