Modified primers for D12S391 and a modified silver staining technique

Ln this paper we describe a new primer pair for the short tandem repeat (STR) D12S391 which makes it possible to obtain considerably shorter amplification fragments (125-173 bp), compared to the previously published primers (205-253 bp). The primers were tested on 70 samples with known genotypes, and no differing results were found. In sensitivity studies, forensic casework samples and DNA quality studies, we proved that the new primers can improve the efficiency of the amplification. Moreover, the resolution of this locus on denaturing PAGE followed by silver staining was dramatically improved. This improvement was found to be most valuable for typing the rare .3 variants known for this locus. We also present and propose a new method for silver staining denaturing acrylamide gels.