Methods for long-term virus preservation.

Viruses exhibit a wide variety of structural and chemical differences, but, in general, their infectivity may be destroyed by degradative enzymes that destroy nucleic acids, by detergents that solubilize the lipid-containing envelopes thus exposing the nucleic acid, by temperatures higher than about 50 degrees C, or by chemicals that breakdown capsid proteins. Preserving the viruses at low or ultra-low temperatures, and/or in the absence of water, slows down these destructive processes sufficiently to increase significantly the length of time that the virus can be stored as infectious material. Supplements such as serum are presumed to stabilize the environmental conditions and to block degradative processes. The methods by which viruses may be preserved for long periods of time are similar to those employed for other microorganisms and are relatively simple. Nevertheless, attention to detail, good laboratory practice, aseptic technique, meticulous recordkeeping, and regular monitoring of the stored materials will increase the success rate and reduce problems of contamination or loss in the storage containers, where many different viruses may be stored for posterity! This article describes some of the simplest and most reliable storage procedures for viruses, but the author recognizes that everyone will have a favorite method to suit his or her own particular virus.