DNA has been shown to be stable in dried semen and blood, and it is important to demonstrate that frequently encountered environmental conditions will not adversely affect the restriction fragment-length polymorphisms (RFLP) patterns produced. The experiments were designed to study the effects of ultraviolet light (for up to five days), heat (37 degrees C), humidity (0, 33, 67, and 98 percent), and soil contamination on the integrity of DNA in dried specimens and to determine if the RFLP pattern produced under the experimental condition varied from those of the control samples. Also examined was the effect of drying over a four-day period in whole blood collected with and without ethylenediamine-tetraacetate (EDTA). The results showed that under the conditions studied, the integrity of DNA was not altered such that false RFLP patterns were obtained. The only observed effect was that the overall RFLP pattern becomes weaker, but individual RFLP patterns were neither created nor destroyed. 7 figures, 13 references. (Author abstract modified)