A simple method for the preparation of extracts from animal cells which catalyze efficient in vitro protein synthesis.

A rapid, simple procedure is described for the preparation of cell-free extracts of both uninfected and virus-infected pig kidney and baby hamster kidney cells which are very active in the in vitro translation of not only endogenous mRNA, but also of exogenous mRNA added to extracts that had been depleted of endogenous mRNA by treatment with micrococcal nuclease. This procedure appears to be adaptable with only minor variations to many eukaryotic cell lines and should greatly facilitate in vitro molecular studies of protein synthesis and gene regulation at the level of translation.