How stable are GENTEST microsome products?
All GENTEST microsome products are stable for at least two years when stored at -80C. To date, no microsome product has shown a significant loss in enzyme activity when stored at -80C for two years. Two papers which describe the stability of P450s in human liver microsomes have recently been published. Both papers state that there was no significant decrease in P450 activity after 10 freeze/thaw cycles or storage of the microsomes at -80° C for five years. “Effects of Freezing, Thawing, and Storing Human Liver Microsomes on Cytochrome P450 Activity, Robin E. Pearce et al., (1996) Arch. Biochem. Biophys., 331, 145-169. and “Effects of Freezing, Thawing, and Storage of Human Liver Samples on the Microsomal Contents and Activities of Cytochrome P450 Enzymes”, Hiroshi Yamazaki, et al., (1997) Drug Metab. Dispos. 25, 168-174. Cytochrome P450s are known to lose their activity after thawing. We strongly recommend quickly thawing GENTEST microsomes, placing them on ice, and then freezing the m
