Differential display PCR (DD-PCR) is an mRNA fingerprinting technique to identify differentially expressed genes by comparative display of arbitrarily amplified cDNA subsets. This attractively simple screening method was, however, followed by a labour intensive multistep identification procedure for DD-PCR products. In this report we demonstrate for the mouse mast cell protease 2 (MMCP-2) and the cytotoxic T-lymphocyte associated gene transcript CTLA-1 a streamlined approach by (i) direct cycle sequencing with the upstream differential display (DD) primer, followed by (ii) the PCR based generation of an antisense northern probe with the downstream anchor primer.