Under the current epidemic, nucleic acid testing has attracted attention from all walks of life as a diagnostic method for rapid diagnosis of new coronavirus pneumonia. There are many factors that affect the results of nucleic acid testing, including sample collection location, collection method, storage and transportation process, nucleic acid extraction operation, and so on. Among them, the stability of the sample is a key link. Today, the editor will explain to you how the RNA storage solution that can not only inactivate the virus quickly, but also protect the viral nucleic acid and maintain the stability of detection, works.

The first step: break the shell and eliminate "combat power"

Like other RNA viruses, the results of the new coronavirus are simply composed of a protein shell wrapped in single-stranded nucleic acid-RNA. We can simply think of the RNA of the virus as the "brain" that gives orders, and the protein is the "limbs" that execute the orders. The new coronavirus infects the human body and reproduces, causing symptoms. This process is mainly completed by the biologically active protein structure outside the virus. To

Schematic diagram of virus structure

The composition of the inactivated RNA virus transport media contains a high concentration of lysis salt, which is a powerful protein denaturant that can quickly dissolve the protein and cause the virus structure to break. When the clinical sample with the new coronavirus is mixed with the preservation solution, the virus in the sample is affected by the lysis salt, and the protein shell is quickly destroyed, and this damage is irreversible. At this time, the virus has lost its evil "minions" and no longer has the ability to infect people, thus ensuring the safety of contacts during sample transportation and processing.

Step 2: Inhibit enzyme activity and escort "ID card"

After the shell is lysed, the RNA of the new coronavirus is free in the preservation solution. As a single-stranded macromolecule, the stability of RNA is not as immobile as double-stranded DNA. The RNase that exists everywhere in the natural environment is the culprit that causes RNA to hydrolyze and break. Therefore, it is generally considered that the viral RNA that has lost its outer shell protection is fragile and unstable, and requires low-temperature storage to ensure its integrity. To

In this case, isn't the viral RNA in the RNA storage solution at risk? However, the truth is that the RNA preservation solution is designed to protect fragile RNA: RNase, as a protein, will also be destroyed by high concentrations of lysis salt. At the same time, other types of RNA protective agents are added to the preservation solution. Through various means, the "identity certificate" of the RNA virus is fully protected.

Desheng Technology's RNA storage solution has been verified by laboratory stability. It can maintain the PCR results of sample detection for at least 7 days under destructive conditions of 34°C, and can be stored for longer at room temperature. This step solves the limitation that samples have to be refrigerated or even frozen for transportation and storage for stability, and it is more convenient for hospitals to carry out a large number of transport and testing.

The third step: cooperate with the extraction to confirm the "true culprit"

Viral RNA is properly stored in the transport media. Before testing, the final step is required: capturing and concentrating the RNA in the preservation solution, adding it to the real-time fluorescent PCR system as the final sample, and testing on the machine. Desheng Technology's RNA storage solution can be used in conjunction with the ABC method nucleic acid extraction reagent, the ordinary magnetic bead method nucleic acid extraction reagent, and the magnetic bead method automatic nucleic acid extractor to further improve the detection efficiency.