PCR is used as a preparative tool for the synthesis of a high-complexity double-stranded DNA library. In the example presented here, a mixture of synthetic oligonucleotides is used to synthesize a random peptide NNK library, where K is either T or G. The exclusion of A and C nucleotides at the third position decreases the occurrence of stop codons but still allows codons for all 20 amino acids. - [Read Use of PCR to Prepare a Double-Stranded DNA Library Encoding Random Peptides Protocol]
This protocol a protocol on how to generate transfected embryonic stem (ES) cell clones. The previous protocol in this series is the Protocol for Electroporation of ES cells. The next protocol in the series is the Protocol on Disaggregation, Expansion, and Freezing of Transfected ES Clones.