Glycerol has been used for a long time as a viral preservation medium in tissue samples at a 50 per cent concentration, however after a limited time span viruses could no longer be detected. This fact combined with the dehydrating action of glycerol, raised the suspicion that glycerol in a higher concentration could be virucidal. To test this hypothesis, experiments were done at various concentrations of glycerol at three different temperatures (4, 20 and 37 degrees C), using the following viruses: herpes simplex virus, a virus with an envelope, comparable to human immunodeficiency virus; and poliovirus as an example of small, hard to inactivate viruses without an envelope. Glycerol will dehydrate the skin, the extracted water being replaced by glycerol, preserving the original structure. The remaining water is optimally distributed throughout the tissue. However, the possibility exists that glycerol influences the enzymatic processes of nucleic acid breakdown. Plasmid DNA pBR322 was added to HeLa-cells in the presence and absence of glycerol. The outcome of the experiments showed that glycerol has a strong virucidal action. Preservation in 85 per cent glycerol was preferred, because using this concentration the glycerolized allograft skin retained its suppleness and was easy to manipulate during operations.