PCR Cloning of Human Immunoglobulin Genes

One of the first steps in an antibody-engineering project is the isolation of the immunoglobulin heavy (V_H )- and light (V_L )-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 V_H and V_L 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 ).