What is nucleic acid testing?
What is nucleic acid testing?
Nucleic acid testing is to find out whether there is nucleic acid of foreign invading viruses in patients' respiratory specimens, blood or feces to determine whether they are infected with the new coronavirus. Therefore, once the nucleic acid is detected as "positive", it can be proved that the virus exists in the patient.
Collection of nucleic acid test samples
1. Nasopharyngeal swab: The sampler gently supports the head of the person to be collected with one hand, and holds the swab in the other hand. The swab is inserted into the nostril, and slowly penetrates backward along the bottom of the lower nasal passage. Because the nasal passage is curved, it cannot be used. Use too much force to avoid traumatic bleeding. When the top of the swab reaches the posterior wall of the nasopharyngeal cavity, gently rotate it for a week (in case of reflex cough, it should stay for a while), then slowly take out the swab, and immerse the swab head in 2-3 ml of virus preservation solution (or Use isotonic saline, tissue culture, or phosphate buffer), discard the tail, and screw the cap tightly.
2. Throat swab: The person being collected first gargles with physiological saline, and the person collecting the swab is moistened with sterile normal saline (it is forbidden to put the swab in the virus preservation solution to avoid allergies caused by antibiotics), and the person being collected The head is slightly tilted, the mouth is wide open, and an "ah" sound is heard, exposing the pharyngeal tonsils on both sides, passing the swab over the base of the tongue, and wiping the pharyngeal tonsils on both sides of the subject with slight force for at least 3 times, and then wiping up and down the posterior pharyngeal wall At least 3 times, immerse the swab head into a tube containing 2-3 ml of virus preservation solution (isotonic saline solution, tissue culture solution or phosphate buffer can also be used), discard the tail, and tighten the tube cap. Throat swabs can also be placed in the same tube as nasopharyngeal swabs.
3. Nasopharyngeal or respiratory tract extracts: Mucus is drawn from the nasopharynx or respiratory secretions from the trachea with a collector connected to a negative pressure pump. Insert the head of the collector into the nasal cavity or trachea, turn on the negative pressure, rotate the head of the collector and withdraw slowly, collect the extracted mucus, and rinse the collector once with 3ml of sampling solution (you can also use a pediatric catheter to connect it to a 50ml syringe. alternative collector).
4. Deep cough sputum: After the patient is required to cough deeply, collect the coughed up sputum in a sampling tube containing 3ml of sampling solution. If the sputum is not collected in the sampling solution, 2-3 ml of sampling solution can be added before the test, or an equal volume of sputum digestion solution can be added.
5. Bronchial lavage: insert the head of the collector into the trachea (about 30cm deep) from the nostril or tracheal socket, inject 5ml of normal saline, turn on the negative pressure, rotate the head of the collector and exit slowly to collect the extracted mucus , and flush the collector once with the sampling solution, or use a pediatric urinary catheter connected to a 50ml syringe to replace the collection.
6. Bronchoalveolar lavage fluid: after local anesthesia, insert a fiberoptic bronchoscope through the mouth or nose through the pharynx into the bronchus of the right middle lobe or the lingual segment of the left lung, insert the top of the bronchial branch into the opening of the bronchial branch, and slowly add sterilant through the tracheal biopsy hole. Bacterial saline, 30-50ml each time, total 100-250ml, should not exceed 300ml.
7. Fecal specimens: Take 1ml of specimen treatment solution, pick the size of soybean grains and add them to the tube, gently blow and suck 3-5 times, let stand for 10 minutes at room temperature, centrifuge at 8000 rpm for 5 minutes, and absorb the supernatant test.
8. Anal swab: Use a sterile cotton swab to gently insert into the anus for 3-5cm, then gently rotate to pull out, immediately put it into a 15ml outer screw-cap sampling tube containing 3-5ml of virus preservation solution, discard the tail, and spin the swab. Tighten the cap.
9. Blood sample: It is recommended to use a vacuum tube containing EDTA anticoagulant to collect 5ml of blood sample, and to use whole blood or plasma for nucleic acid extraction according to the type of nucleic acid extraction reagent selected. To separate the plasma, centrifuge the whole blood at 1500-2000 rpm for 10 minutes, and collect the supernatant in a sterile screw-top plastic tube.
10. Serum samples: collect 5ml blood samples with a vacuum negative pressure blood collection tube, stand at room temperature for 30 minutes, centrifuge at 1500-2000 rpm for 10 minutes, and collect serum in a sterile screw plastic tube.
Manufacturer of VTM:
Geneture medical specialized in the field of nucleic acid extraction and PCR detection system, main products involved in：
1.Nucleic Acid Extraction Kit (Magnetic beads method)
2.Nucleic Acid Extractor （32T, 96T）
3.PCR fluorescence quantitative analyzer (16T, 96T)
4.PCR detection reagent
5.SARS-CoV-2 antigen rapid test kit
6.Lab consumables: deep well plate, mag-rod sleeve, pipette tips, VTM, swabs, PCR tubes, PCR plate, centrifuge tubes, cryogenic Vials, saliva collection and so on.
Please don’t hesitate to contact with us to get a quotation.