Heteroduplex PCR analysis of Dh7-27-Jhcross-lineage rearrangements in T-ALL. Subsequent to agarose gel electrophoresis, samples containing PCR products were subjected to heteroduplex PCR analysis, separated in a 6% polyacrylamide gel, and visualized by ethidium bromide staining. Based on the size of clonal PCR products, Dh7-27-Jh rearrangements (∼250 bp) were identified in T-ALL patients T009, T038, T042, T062, T150, and T184 as well as in a T-cell prolymphocytic leukemia (T-PLL). In addition to homoduplexes resulting from Dh7-27-Jhrearrangement, the germline Dh7-27-Jh1 and Dh7-27-Jh2 homoduplexes were consistently present, except for cases with biallelic IGH rearrangements and a very high tumor load (ie, patient T150). To obtain a clonal sequence of Dh7-27-Jh rearrangements, homoduplexes of the correct size were excised from the polyacrylamide gel, eluted, and sequenced. ss, single-strand DNA.