Why is the Preservation Solution in the Virus Transport Medium Colored?

Why is the preservation solution in the virus Transport Medium colored?

Virus preservation solution is also called nucleic acid preservation solution and sample preservation solution. It is usually divided into inactivated type and non inactivated type. Generally, inactivated preservation solution is colorless, because the components of inactivated preservation solution are generally colorless. The colored preservation solution is due to the addition of pH indicator phenol red. Phenol red shows yellow when it is acidic, red when it is neutral and purplish red when it is alkaline. Other types of indicators are similar. By observing the color change, we can quickly judge whether the pH value of the virus preservation solution has changed or whether there are long bacteria and deterioration.

Because the inactivated virus preservation solution is to inactivate the virus or bacteria to avoid secondary infection, some cleavage salt or guanidine salt will be added to achieve the effect of inactivating the virus.
The difference between non inactivated virus preservation solution and inactivated virus preservation solution is that it does not need to inactivate the virus, but to prolong the survival time of the virus in vitro and maintain the complete characteristics of the virus, so as to improve the accuracy of nucleic acid detection or do other research that does not just retain the nucleic acid of the virus.
The virus cannot survive in vitro and must parasitize in living cells, so the non inactivated virus preservation solution will add some liquid components that can prolong the survival time of virus parasitic cells, so as to indirectly improve the virus survival rate. In addition, the preservation solution also contains a variety of amino acids, glucose, sucrose, protein and other nutrients. These factors make it easier for non inactivated virus preservation solution to breed bacteria or deteriorate than inactivated virus preservation solution.