RNA/DNA co-analysis from blood stains--results of a second collaborative EDNAP exercise.

A second collaborative exercise on RNA/DNA co-analysis for body fluid identification and STR profiling was organized by the European DNA Profiling Group (EDNAP). Six human blood stains, two blood dilution series (5-0.001 µl blood) and, optionally, bona fide or mock casework samples of human or non-human origin were analyzed by the participating laboratories using a RNA/DNA co-extraction or solely RNA extraction method. Two novel mRNA multiplexes were used for the identification of blood: a highly sensitive duplex (HBA, HBB) and a moderately sensitive pentaplex (ALAS2, CD3G, ANK1, SPTB and PBGD). The laboratories used different chemistries and instrumentation. All of the 18 participating laboratories were able to successfully isolate and detect mRNA in dried blood stains. Thirteen laboratories simultaneously extracted RNA and DNA from individual stains and were able to utilize mRNA profiling to confirm the presence of blood and to obtain autosomal STR profiles from the blood stain donors. The positive identification of blood and good quality DNA profiles were also obtained from old and compromised casework samples. The method proved to be reproducible and sensitive using different analysis strategies. The results of this collaborative exercise involving a RNA/DNA co-extraction strategy support the potential use of an mRNA based system for the identification of blood in forensic casework that is compatible with current DNA analysis methodology.

Successful DNA typing of ultrafiltered urines used to detect EPO doping.

Endogenous and exogenous erythropoietin (EPO) present in urine can be distinguished according to their isoelectric profiles. This methodology requires urine samples to be concentrated about 200 to 1000 times with manipulations that should remove most of the cells occurring in the original sample. In this study, we tried to obtain DNA profiles from 10 ultrafiltered urines (retentates) in order to evaluate whether a formal genetic identification was technically feasible. No nuclear DNA profiles could be established from retentates, despite 34 PCR-cycles amplifications. Contrastingly, mitochondrial DNA (mtDNA) profiles were obtained for 9 out of the 10 retentates. Apart from some particularities, retentate mtDNA profiles were all distinct and matched mtDNA profiles of corresponding reference samples.