Definition of Viral Transport Media (VTM)

A viral transport media (VTM) is a nutrient substance that is used to transport and keep the viability of specimens (viruses) to a laboratory for identification and further processing.

Virus transport media are especially important because viruses are more labile than other infectious agents.
When the time interval between collection and inoculation of the culture is short and the specimen contains as many virus particles as possible, the likelihood of successful isolation increases.
To maximize the amount of virus in the specimen, the sample should be collected early in the patient's illness.

When a suitable transport medium is used, virus isolation can be accomplished successfully and reliably.
When viral specimens are sent to a local laboratory or a reference laboratory, the isolation count rises.