Influence of calcium concentration and centrifugation speed/time on the isolation yield of rat liver microsomes

Abstract

 In view that microsomes isolated from rat liver have crucial application in drug development such as evaluating drug metabolism and drug influence on CYP450s, and currently, two common isolation methods are ultracentrifugation and calcium aggregation, for application of the latter one for microsome isolation, the effect of calcium concentration and centrifugation speed/time on the yield of microsome isolation were investigated. Addition of Ca²⁺ to the postmitochondrial supernatant up to 4 mM or higher and the centrifugal force ≥ 25000 g resulted in high yield of microsomes (> 18 mg protein/g liver). Also, the centrigugation time of 15 mins is just sufficient to precipitate microsomes from the postmitochondrial supernatants.