A recently developed assay for measuring infectious HIV-1 particles was used to determine the stability of the virus under various storage conditions as well as the effect of commonly used disinfectants. At the optimum pH of 7.1 the half life of the virus ranged from approx. twenty-four hours at 37 degrees C to no significant loss over 6 months at -75 degrees C. Drying the virus on a glass surface or freezing caused a 5-12 fold and 4-5 fold decrease of activity, respectively. The dried preparations, however, were about as stable as when stored in a buffered solution. A solution of iodine and detergent (2% Jodopax) was the only disinfectant examined which removed all detectable HIV-1 activity. Isopropanol and ethanol were more potent than acetone; however, all three solvents left some viable particles after a 30 min treatment with 70% solutions.