Constructions of gene libraries of Rana nigromaculata and Mus musculus with cosmid pHC79.

Gene libraries of Rana nigromaculata and Mus musculus (C57J6) have been constructed by the cosmid system developed by Collins using BamHl and Pstl as cloning restriction enzymes. A simplified formula, which is a modification of Clarke and Carbon derived from approximation, was used for calculating the number of colonies or recombinants necessary for the construction of a gene library. Pro+ and leu+ complementary to the recipient cells (HB101) with the genetic constitution of pro- and leu- have been selected from the BamH1 gene libraries of both Rana nigromaculata and the mouse in the present work.