Since the identification of a sample as non-menstrual can be
expected to have similar or even higher significance than to
prove that it is menstrual blood, it would obviously be of crucial
importance to establish criteria which could improve the
evidential value of negative test results. In this context it seems
to be equally important to optimize RNA isolation and
amplification because of the frequently encountered small size
of forensic samples.
The availability of real time-PCR has already revolutionized
many areas of forensic science from forensic pathology [6] to
DNA analysis [7] and represents an elegant tool to deal with the
technical limitations of the gel-based method: it is quantitative,
it is highly specific and sensitive when using dual-labelled
probes for detection of the amplification products and it
provides clear-cut and objective results.
Therefore, the aim of this study was two-fold: to establish a
real time-PCR-based assay for the detection methods for
menstrual blood and to provide data for a better differentiation
between true positive and negative results using quantitative
real time RT-PCR.