P-32 INCORPORATION PCR FOR THE DETECTION OF REARRANGEMENTS AT THE TCR-GAMMA LOCUS

We have adapted and developed a PCR (polymerase chain reaction)-based technique for the T-cell receptor (TCR)-gamma chain gene, which has su bsequently been used for routine diagnosis. Variable-region oligonucle otide primers were chosen from subgroups I and II, and the joining reg ion primer was from the J(2) segment. The primers were used to perform a P-32-incorporation PCR, and the products were then separated on an 8% denaturing polyacrylamide gel. In our hands, this technique is more reliable than cold methods, when separation is performed on either ag arose or nondenaturing polyacrylamide. The radioactive technique was u sed to look at 102 T-cell proliferations, of which eight of eight T-ac ute lymphoblastic leukemia (ALL), 24 of 34 T-non-Hodgkin's leukemia (N HL), and 35 of 60 large granular lymphocyte (LGL) expansions were clon al. Of 122 B-cell proliferations investigated, including 72 cases of B -cell lineage ALL, 36 demonstrated a T-cell rearrangement (33 ALLs and three myelomas). Samples from nonlymphoid tumors were tested and prod uced a normal distribution ladder of PCR products after autoradiograph y, a pattern also observed with antenatal and preoperative patients. T he radiolabel-incorporation method detected an abnormal pattern of a l adder with prominent dark bands in 29 of 122 B-cell and 27 of 102 T-ce ll cases and in 0 of 49 of the nonlymphoid and normal samples. The abn ormal banding patterns obtained in a proportion of the B- and T-cell c ases was not readily discernible by nondenaturing-acrylamide or agaros e-separation methods.