DESCRIPTION: (Adapted from applicant's description) This new Core is intended to provide technical expertise and advice on current molecular biological techniques, including phage display, differential display reverse transcription polymerase chain reaction, library generation and screening, targeted gene expression and homologous recombination. In addition, the core staff have expertise in primer design for both PCR and sequencing reactions, PCR trouble shooting, molecular cloning and plasmid selection, as well as in the generation of gene targeting and tissue targeting vectors for rodent transgenesis.