Simplified mammalian DNA isolation procedure.

The reverse genetics technologies that have recently been developed for mice have provided new tools to probe gene function in vivo. Unfortunately these powerful systems often require the analysis of large numbers of DNA samples. The genetargeting technology requires screening of embryonic stem-cell clones and later of the mice themselves, the latter also being the case for standard transgenic technology. It is not always possible or desirable to rely on PCR analyses, necessitating the isolation of large numbers of DNA samples of sufficient quality for Southern blot analysis. We have simplified the standard mammalian DNA isolation procedure with the aim of minimizing the number of manipulations required for each sample. The basic procedure applied to cultured cells does not require any centrifugation steps or organic solvent extractions.