Sterilization and Storage of Saliva

¹ Department of Microbiology, University of Alabama Medical Center, Birmingham, Alabama, and Veterans Administration Hospital, Birmingham, Alabama

Five methods were tested for their effectiveness in sterilizing saliva and were evaluated according to the extent of denaturation they produced. Denaturation was measured by changes in activities of three enzymes and concentrations of specific plasma proteins and other antigenic substances. The effects of 24 hours' storage on liquid saliva and on frozen or freeze-dried saliva were evaluated by the same criteria. Methods that either did not sterilize or that denatured excessively were hydrogenperoxide treatment, gamma irradiation, and filtration. Sterility of saliva with minimal denaturation was obtained in approximately 85 per cent of tests using 21 minutes' ultraviolet irradiation of thin layers and in more than 85 per cent of tests using treatment with 3 per cent ethylene oxide for 1 hour at 4° C. followed by 4 hours at 3° C. Storage at or below freezing temperatures and sterilization either by ultraviolet irradiation or by ethylene-oxide treatment help to retard denaturation of saliva.