We have designed and tested primers that amplify complete human kappa and lambda light chain genes, and human Fd fragments from gamma, mu and alpha heavy chain genes. These primers were tested for efficiency and specificity on monoclonal sources of human immunoglobulin RNA, obtained from human B-cell lines of known immunoglobulin gene expression. Analysis of the sequences derived from these B-cells confirms the specificity of the PCR primers and the extent of somatic mutation seen in different B-cell malignancies supports existing concepts for differing aetiologies in the tumours concerned.