[75] Assay of transforming activity of tumor virus DNA

Publisher This chapter describes the assay of transforming activity of tumor virus DNA. Several techniques have been developed for assaying biological activity of DNA extracted from mammalian viruses. These methods measure the infectivity of viral nucleic acid preparations in cultured cells. This technique was developed as an assay for infectivity of adenovirus DNA, which also appeared suitable for demonstrating transformation with several viral DNAs. The diethylaminoethanol (DEAE)-dextran and the calcium technique have been used in virus research. A possible reason for the failure to obtain transformation with the DEAE-dextran technique may be the relative toxicity of this compound for many cultured cells. The chapter describes the procedures for assaying transformation of cultured cells by viral DNA or DNA fragments, in particular of adenovirus and SV40 DNA. The only method suitable for the demonstration of transforming activity with these viral DNAs is the calcium technique, therefore, the chapter discusses this method and the modifications developed to enhance its effectiveness.