EFFECT OF STORAGE-CONDITIONS ON THE MUTAGENICITY OF HUMAN URINE

Effects of storage conditions on the mutagenicity of human (2 smokers and 3 nonsmokers) urine were examined. Aliquots of urine from each mal e volunteer were stored at -80, 3, 25 and 40 degrees C for various tim e points (max. 4 or 8 weeks). All extracts were obtained by the use of the Sep-pak tC(18)/methanol method. At the end of maximum time points , all extracts were assayed by the pre-incubation method with Salmonel la typhimurium YG1024. Some statistical changes of mutagenicity were o bserved under the storage conditions with 25 and/or 40 degrees C for 1 or 2 weeks by the analysis of variance techniques. However, no statis tical changes were observed under -80 and 3 degrees C at least up to 4 weeks (significance level: 0.01). It was suggested that human urine s amples for the mutagenicity assay may be practically stored at 3 degre es C at least for 4 weeks.