Abstract: A technique and receptacle for disinfecting biological fluids such as whole blood is described in which the disinfectant is prepositioned in a receptacle for biological fluids utilized for clinical evaluation in an amount which is sufficient to disinfect the fluid without interfering with subsequent clinical evaluation. The invention is specifically directed to disinfecting viral contaminants in blood by providing a closed container for the blood specimen which contains an amount of a disinfectant sufficient to destroy without otherwise affecting the integrity of the specimen for future evaluation. The amount of disinfectant positioned in the container is adjusted to provide an ultimate concentration in the blood specimen of aldehyde of about 0.001 to 5.0 weight percent and is buffered to a pH of about 7.2 to 8.5 percent preferably about 7.4.