Volume 49, Issue 6 (November 2004)
Successful Identification of Two Years Old Menstrual Bloodstain by Using MMP-11 Shorter Amplicons
Sir, Recently mRNA amplification of biological stains has become a convincing instrument for body fluid identification in forensic casework (1). mRNA recovery in sufficient quantity and quality for RT-PCR analysis and its stability in biological stains up to 15 years were demonstrated by Bauer et al. (2). These authors developed a powerful protocol to detect endometrial cells on dried menstrual bloodstains via RT-PCR of several markers among which metalloproteinase 11 (MMP-11) was found to be sensitive andtissue-specific (3,4). This protocol was successfully applied in our experimental studies on laboratory prepared menstrual bloodstains aged up to 1 year to amplify MMP11 and Er-1 receptor gene (data not shown), but in a two years old sample, consisting of knickers with a presumed large spread menstrual bloodstain mixed with urine and stored dried at room temperature, the results were not reproducible and in multiple assays, and although the housekeeping gene was positive, MMP-11 amplification failed even to increase the size of the sample. Despite the interpretation of MMP-11 negative results (4), we modified the original protocol consisting of 55 cycles amplification for a 455 bp PCR product to achieve a more sensitive detection approach.