Virus sampling tube is a medical device product, domestic manufacturers mostly according to a product for the record, but very few companies according to two products for registration. Many companies applied for a filing permit through the "emergency channel". Virus sampling tube consists of a sampling wiper, virus preservation solution, packaging, etc.
Due to the lack of uniform national standards and industry standards, the products of various manufacturers vary greatly, so, together with the following to understand what needs to be noted in the production and use of virus sampling tubes!
1, sampling wipers: sampling wipers are in direct contact with the sampling site, and the material of its sampling head is closely related to the subsequent inspection. The material of the rod head must also not be cotton products. Wooden sticks and bamboo sticks containing calcium alginate and wooden components break, because the fibers of cotton are strong in protein adsorption, it is difficult to dissolve into the subsequent preservation solution. Natural fibers such as cotton or nylon-like fibers are not recommended. Nylon type fibers (similar to toothbrush heads) have poor water absorption and will also adsorb proteins when immersed in the preservation solution, inhibiting subsequent PCR reactions.
The recommended materials for producing wiper heads are PE fibers, polyester fibers, polypropylene fibers and other synthetic fibers. Therefore the sampling volume is insufficient, affecting the detection rate.
2, virus preservation solution: There are two main types of virus preservation solution widely used in the market, one is a modified virus preservation solution based on handling medium, and the other is a modified preservation solution for nucleic acid extraction lysate.
Preservation solution is nutrient-rich and conducive to the survival of viruses.
Through the carbon dioxide in its metabolites, the pH of the preservation solution will drop, but it is also conducive to the growth of bacteria, so the bacteria in the preservation solution will proliferate and turn from pink to yellow after being contaminated. Therefore, while the use of inhibitors such as sodium adipate, 2-methyl-4-isothiazolin-3-one (MCI ) and 5-chloro-2-methyl-4-isothiazolin-3-one) CMCI ), many manufacturers have added antimicrobial components to their formulations, and the recommended antimicrobial agents are penicillin, streptomycin, gentamicin and polyinosinic acid b.
The assay body provided by this preservation solution is essentially live however, the It is important to note that when used for examination, nucleic acid extraction and purification is performed after inactivation.
The metal ion blocker used in the virus preservation solution is recommended to use EDTA salts, in order not to affect the nucleic acid detection, the use of heparin class) heparin, heparin, etc.
3. Preservation tubes: The material used to manufacture preservation tubes should be selected with care. When using collapsible wipers, preservation tubes should try to select containers with a height of 8 cm or more to avoid contamination of the contents from flying outward when folding the wipers.
4. Water used in the production of preservation solutions (ultrapure water used in the production of preservation solutions, in order to effectively remove polymeric impurities from RNase, DNase, endotoxin and other organisms, molecular weight 13,000 ultrafiltration membrane for filtration. It is not recommended to use ordinary pure water or distilled water.
Second, the use of virus sampling tubes
Virus sampling tubes are used for sampling mainly divided into oropharyngeal sampling and nasopharyngeal sampling.
1, pharyngeal collection: after pressing the tongue with the tongue pressure plate, put the head of the collection wiper into the pharynx to wipe the bilateral pharyngeal tonsils and the posterior pharyngeal wall, and gently and forcefully wipe the posterior pharyngeal wall so as not to touch the tongue.
2、Nasopharyngeal collection: measure the distance from the tip of the nose to the earlobe with the wiper, mark it with your finger, and insert the collected wiper into the nasal cavity along the vertical nose (face) direction. Insert the wiper to half of the length from the earlobe to the tip of the nose, stay in the nose for 15-30 seconds, and gently rotate 3-5 times to pull out the wiper.
As can be seen from the method used, the quality of the collected specimen is directly related to the subsequent examination. If the collected specimen has a low viral load, whether it is an oropharyngeal swab or a nasopharyngeal swab, sampling is a technical task, difficult and easily contaminated, it is easy to be false negative and difficult to confirm the diagnosis.
Most of the specimens recommended by the kits currently on the market are oropharyngeal swabs or nasopharyngeal swabs and alveolar lavage fluid. Originally, venous blood samples are not difficult to collect, and just like detecting RNA for hepatitis C, separating plasma from about 5 ml of EDTA-anticoagulated blood samples can greatly reduce the work of the collector if the blood is collected with venous specimens, especially special nucleic acid detection tubes, and purified RNA is extracted and examined.
The extracted and purified RNA can fully meet the needs of nucleic acid testing.
Diagnostic reagent development companies, medical institutions, and research institutions are expecting to launch high-sensitivity kits that can cope with a variety of tests as soon as possible, and to verify the correlation between oropharyngeal swab test results and venous blood test results as soon as possible.
The above introduction is the virus sampling tube production and use need to pay attention to what, for more information, feel free to contact us!
