Selective differential fingerprinting. A method for identifying differentially expressed genes in a family between two samples.

A method termed selective differential fingerprinting (SDF) has been developed that enables one to investigate the level of expression for a family of genes between two samples. SDF produces a fingerprint (on a sequencing gel) on reverse transcription polymerase chain reaction (RT-PCR) of a sample with degenerate primers designed from conserved regions of a family of genes. By comparing fingerprints obtained after SDF with primers representing the transforming growth factor-beta (TGF beta) family of growth factors between a low-grade and a high-grade tumor from the same patient, a TGF beta family member known as osteogenic protein 1 (OP-1) or bone morphogenic protein 7 (BMP-7) was found to be greatly overexpressed in the high-grade tumor compared to the low-grade one. SDF also has the potential to identify novel genes. SDF offers a general way to identify differentially expressed genes for a family between two given samples.