Screening for amplification of specific DNA sequences in cultured mammalian cells.

Carcinogen- or herpes virus-induced amplification of integrated simian virus 40 DNA in transformed cell lines has been demonstrated previously by Southern blot analyses, dot hybridizations, and dispersed cell assays. Although these methods are quite reliable, large series of experiments require a considerable amount of time and effort. Therefore, an alternative method has been developed that allows one to carry out great numbers of separate gene-amplification experiments in the 96 wells of microtiter plates and to analyze the DNAs of the treated cells simultaneously after "replica blotting" onto membrane filters by hybridization with a cloned DNA probe.