Digoxigenin-labeled probes amplified from genomic DNA detect T-cell gene rearrangements

The detection of clonal rearrangements of the human T-cell receptor by Southern hybridization is a useful tool to diagnose morphologically difficult lymphoid proliferations. Widespread application of this method has been facilitated by the advent of sensitive nonradiolabeled probes. Although a limited number of nonradiolabeled DNA probes are commercially available, other probes must be obtained through a time-consuming and technically difficult procedure of amplification, isolation, and labeling of plasmid-cloned DNA sequences. A simple and time-saving procedure to simultaneously amplify and nonradioactively label DNA probes for use in gene rearrangement studies is described. Specifically, a method using the polymerase chain reaction to amplify and label with digoxigenin large quantities of probe to the constant region of the T-cell receptor directly from genomic DNA is described. The resultant probes are specific for the T-cell receptor-constant region, detect the appropriate germline configuration in placental DNA, and identify rearranged clonal T-cell proliferations. The polymerase chain reaction digoxigenin-labeled probes are suitable for detection by conventional colorimetric methods or by chemiluminescent detection schemes.