PCR Cloning of Human Immunoglobulin Genes

One of the first steps in an antibody-engineering project is the isolation of the immunoglobulin heavy (VH )- and light (VL )-chain variable-region genes that encode the binding domains of an antibody. This is best accomplished using the polymerase chain reaction (PCR). Before PCR, cloning antibody genes was a laborious process, requiring the creation and screening of genomic or cDNA libraries. PCR has streamlined the process considerably, simplifying tasks such as the isolation of VH and VL genes from hybridomas, and allowing entirely new approaches such as generation of large antibody fragment gene repertoires from immunized or na�ve hosts that can be displayed on filamentous phage (antibody phage display; see Chapter 8 ) (1 ) or in other display technologies (e.g., ribosome display; see Chapter 9 ).