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Key points and precautions of nasopharyngeal swab collection

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Precautions of nasopharyngeal swab collection

Sample tube: it shall be a plastic tube with a length of about 10cm, a diameter of about 1.5-2CM, a capacity of 10ml and a nozzle.

With spiral wire and air cushion ring in the pipe cover.

Swab: a swab with a polypropylene rod with a sterile polypropylene fiber head or absorbent cotton head.

Sampling solution: Hank's solution is used. There are semi-finished products on sale or prepared by ourselves.

Preparation of 10 times Hank's mother liquor:

(1) Liquid required:

(Note: preparation of 1% phenol red solution: add 4-7ml NaOH solution of phenol red 1.0g and 1mol / l into the mortar,

Grind to completely dissolve it, dilute it to 100ml with double sliding water, disinfect it under high pressure, and store it at room temperature or 4 ℃)

(2) 10 times Hank's mother liquor preparation method:

① Dissolve the above components in water in turn;

② Slowly add liquid B to liquid a and stir constantly at the same time;

③ Then add liquid C;

④ Add double slip water to 1000ml;

⑤ Pressure filtration sterilization (or add 2ml of chloroform);

⑥ Store at 4 ℃.

Preparation of Hank's solution:

① Add 500ml of 10 times Hank's mother liquor into 4500ml double distilled water and shake well;

② 8 pounds, 20 minutes, autoclaved;

③ Cool to room temperature and use 5.6% NaHCO

Adjust pH value 7.0-7.2;


④ Sub assemble sampling tubes, 4ml in each tube;

⑤ Freeze at - 20 ℃ for standby (if there is no pollution, it can be used for half a year).

Dissolve in 100ml double distilled water and repack,

Preparation of solution: weigh 5.6g NaHCO

(Note: 5.6% NaHCO)

Autoclave and freeze at - 20 ℃ for standby.)

Sampling method:

1. Throat swab:

(1) Fully soak the throat swab in the sampling solution, lift it up and leave the liquid level, and repeatedly squeeze it on the tube wall for several times


(2) Let the patient tilt his head slightly, open his mouth wide, and make an "ah" sound, expose the pharyngeal tonsils on both sides, and hold a swab

Wipe back and forth the pharyngeal tonsils on both sides of the patient with a slight force for at least 3 times, and then wipe up and down the posterior pharyngeal wall for at least 3 times


(3) Immerse the swab head into the sampling solution and contact the swab head with the tube wall several times to keep the specimen as much as possible

In the sampling solution, discard the swab and pinch the tail part.

Nasal swab:

(1) Fully soak the throat swab in the sampling solution, lift it up and leave the liquid level, and repeatedly squeeze it on the tube wall for several times


(2) Let the patient's head relax naturally, stick the swab to the nostril wall, and slowly rotate it into the patient's nostril until it reaches the nose

At the palate, then rotate while wiping and slowly take it out. Wipe the other nostril with the same swab in the same way;

(3) Put the nasal swab into the sampling tube of the collected pharyngeal swab, and the method is synchronous with step IV, 1 and 3.

In this way, there is a pharyngeal swab and a nasal swab in a sampling tube, which is the so-called nasopharyngeal swab tube.


1. The sampling object should be those who have fever ≥ 38 ℃ within 3 days of onset;

2. The sampling solution shall be put in the refrigerator (ice row) and taken to the sampling place.

3. The capacity of the sampling tube should be about 10ml, which should not be too large, so as not to affect the post-processing of the specimen;

4. Plastic pipes shall be used for sampling pipes to prevent accidents during transportation;

5. The rod of nasopharyngeal swab should be lengthened to facilitate sampling;

6. The head of the nasal swab should be made as small as possible to avoid discomfort to the patient's nose during sampling;

7. The liquid in the sampling tube shall not be more than 4ml, so as not to affect the concentration of the sample;

8. If necessary, double nasopharyngeal swabs can be collected as parallel samples;

9. The collected samples should be put in 4 ℃ refrigerator immediately (if there is no refrigerator on site, it can be put into the refrigerator immediately)

It shall be transported to the laboratory in a refrigerator for testing within 24 hours (with a detailed sample registration form attached).

If it cannot be delivered within 24 hours, it shall be stored below - 70 ℃;

10. When there are cases of unexplained pneumonia, tracheal aspirates can be collected.