Acid phosphatase screening - wetting test paper or wetting fabric and test paper?

Detecting and locating semen stains is addressed by identifying the associated acid phosphatase activity of semen. The recovery of semen stains is critical as it can, via DNA testing, address the possible source(s) of the semen and may aid in the interpretation of a case. The purpose of these experiments, carried out on behalf of the Body Fluids Forum, was to consider whether wetting the test paper alone or wetting the semen stained fabric and the test paper affected the detection and location of the semen stains on various fabric types, or the subsequent recovery of spermatozoa from these fabrics. It became evident that the preferred approach varied depending on the fabric type being tested but that more often than not, wetting both the fabric and the test paper had a detrimental effect on the recovery of spermatozoa.