Rapid method for distinguishing clonal from polyclonal B cell populations in surgical biopsy specimens

The polymerase chain reaction (PCR) was used to detect clonal rearrangements of the immunological heavy chain gene in frozen samples of human lymphoid tissue. DNA sequences in rearranged genes were amplified using oligomeric primers predicted from conserved sequences in the variable (VH) and joining (JH) regions. On polyacrylamide gel electrophoresis, polyclonal B cell proliferations showed a "smear", probably due to the variable lengths of the diversity (DH) region genes and the N regions separating the VH and DH and JH regions. In contrast, DNA from B cell lymphomas showed a clear single band in eight out of 10 cases. PCR undertaken on germ line DNA from non-lymphoid tumours showed no detectable bands or smears. The method can be completed within one day of biopsy, compared with several days in the case of conventional DNA blot analysis. Furthermore, it is cheaper, simpler, avoids the need for radioactive materials and requires very small amounts of DNA (about 1 micrograms).