A priori one would therefore expect an
accelerated rate of degradation of DNA in biological stains as the
relative humidity approaches 100%. To determine the range of
natural conditions that allow an adequate stability of DNA in stain
material, blood stains without any stabilizing additives were
incubated at various conditions of relative humidity (RH) and
temperature. The quality and quantity of the remaining DNA was
estimated by the ability to PCR amplify long and short fragments
and by quantitative assessment using real time PCR.