The effect of temperature on Y-chromosome detection in blood stains.

The present investigation is an extension of an earlier work on the effect of various temperatures on Y-chromosome detection. The deteriorating effect of storage at 53 degrees C was again demonstrated. Liquid blood samples stored at 5 degrees C were better preserved with regard to Y-chromosomes than those stored at room temperature. This was in conflict with the earlier results on blood stains. New experiments were therefore performed. The results varied. It is suggested that this variation was due to low temperatures having two contrary effects on the results: the well-known preserving effect on biological material and a previously described constricting effect on the heterochromatic areas of the chromosomes making Y-body detection more difficult.