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Nucleic acid testing is required for the exclusion and diagnosis of viral infections such as new coronaviruses. Due to the nature of nucleic acid itself that is easily degraded, the existing conventional sampling and preservation solutions cannot guarantee that the nucleic acid in the sample will not be degraded, and at the same time cannot inactivate the strong infection that may exist in the sample in time Sexual viruses cause secondary transmission when samples are stored, transported and opened for testing, posing a high risk of infection to medical staff. In response to these problems, Desheng Technology responded quickly and launched a highly efficient and stable virus nucleic acid storage solution in due course.
Viral nucleic acid preservation solution is also called virus sample preservation solution. It is mainly divided into two categories. One is the protection of viral nucleic acid, and the other is the protection of viral functional proteins. However, fish and bear paws cannot have both. The protection of nucleic acids will often damage the function. Protein, while protecting the functional protein, but not protecting the nucleic acid well. The traditional virus nucleic acid preservation solution has a single target function. The nucleic acid protection method is only suitable for PCR detection or other molecular detection, and the protection function protein method is only suitable for the detection of virus antigens or antibodies.
Composition analysis of virus transporattion medium
The design of virus sample preservation solutions that are common in technology or the protection of nucleic acids will point to the protection of viral functional proteins. For example, the sample preservation solution for nucleic acid usually contains the inhibitory effect of dnase/rnase and other functional enzymes, which destroys the functional protein, and the virus sample preservation solution that mainly protects the functional protein has a poor protection effect on the nucleic acid. The first type of virus sample storage buffer is more suitable for the use of PCR methods or other molecular detection methods, while the second type of virus sample storage buffer is more suitable for the detection of virus antigens or antibodies, such as elisa or colloidal gold, fluorescence and other rapid detection usage of.
The components of the virus transporattion medium currently studied are mainly Hank's liquid foundation, gentamicin, fungal antibiotics, BSA (bovine serum albumin fifth component), biological buffer HEPES, amino acids, cryoprotectants, glycerin, etc. Minute
1. Hank's liquid:
Liquid A: Na2HPO4·2H2O 0.06 g KH2PO4 0.06 g MgSO4·7H2O 0.20 g Glucose 1.00 g NaCl 8.00 g triple distilled water 750 ml Liquid B: CaCl 20.14 g triple distilled water 100 ml
Preparation method: ①Slowly add liquid B into liquid A. ②The solubility of 0.35 g of NaHCO3 in 100 ml of triple distilled water at 37°C. ③Use a few drops of NaHCO3 solution to dissolve 0.02 g of phenol red. ④Put the ② and ③ liquid into the ① liquid. ⑤ Make the volume to 1000 ml with three distilled water, mix well, and refrigerate overnight at 4°C. ⑥ Sterilize by filtration, pack into vials, and refrigerate. Note: Phenol red is toxic to cells. In addition to 0.02 g, the dosage in the current experiment is 0.01 g and 0.005 g. There are also BSS solutions without phenol red. The color of BSS varies with the amount of phenol red.
2. Gentamicin and fungal antibiotics: a combination of multiple antibiotics, has antibacterial and antifungal effects;
3. BSA (V): Bovine serum albumin (BSA), also known as the fifth component, as a protein stabilizer, is an albumin in bovine serum. It contains 583 amino acid residues and has a molecular weight of 66.430kDa. The point is 4.7. Bovine serum albumin has a wide range of applications in biochemical experiments. It can form a protective film on the protein shell of the virus, making it difficult to decompose, ensuring the integrity of the virus and increasing the separation rate; it can also be used in western blot As a Blocking agent; BSA is added to the digestion reaction buffer to protect the enzyme by increasing the protein concentration in the solution. Prevent enzyme decomposition and non-specific adsorption, can reduce the denaturation of some enzymes, and can reduce some unfavorable environmental factors such as heating, surface tension and chemical factors.
4. The neutral environment constructed by the biological buffer HEPES and HEPES (4-hydroxyethylpiperazine ethanesulfonic acid) buffer helps increase the survival time of the virus and the stability of infection.
5. Amino acids: provide essential nutrients for virus survival.
6. Cryoprotectant: Usually virus transporattion medium needs to be stored at -70℃. Cryoprotectant can better protect the integrity of the virus. Adding cryoprotectant can protect cells from solution damage and ice crystal damage. The cryoprotectant combines with the water molecules in the solution to produce hydration. The crystallization process of weakening water increases the viscosity of the solution and reduces the formation of ice crystals. At the same time, the cryoprotectant can maintain a certain molar concentration inside and outside the cell to reduce the inside and outside of the cell. The concentration of electrolyte in the uniced solution protects cells from solute damage.
7. Glycerin: Glycerin. Glycerin has the function of nutrient and desiccant. The 50% concentration of glycerol keeps the preserved material in a phase quiescent state. The virus is not resistant to the outside world and is sensitive to temperature.
The inactivated virus sample preservation solution developed and produced by Desheng Company penetrates into the inside of the virus sample, which not only inactivates the infectivity of the virus, but also effectively forms chemical protection for the biological macromolecules and functional protein substances in the virus, and after treatment The samples can be stored and transported conveniently at room temperature for a long time, making scientific research safer and more economical.
Not only that, the virus transporattion medium can quickly inactivate the virus that may exist in the sample, and the sample can be quickly inactivated at the same time, and the source of infection can be quickly cut off to ensure the safety of medical staff. Desheng can provide a variety of packaging specifications to meet the needs of different scenarios. It is convenient to use and easy to operate. After collecting the sample, the medical staff can put the swab directly into the sample preservation tube liquid. Its stability is high and it can be used in normal temperature conditions. The samples can be transported down and stored, and nucleic acid can be stored stably for a long time, effectively improving the detection rate.
