Amylase levels in semen and saliva stains.

Amylase levels were determined for 148 semen samples and 20 saliva samples as well as for their corresponding stains. The effect of aging on the detectability of amylase activity in these stains was also investigated. The Phadebas amylase test was used for the quantitative assay of amylase. High levels of amylase in fluid saliva resulted in high levels being detected in saliva stains. Lower levels present in most seminal fluids produce little or no detectable amounts of amylase in stains. Interpretations are made as to the possible sources of amylase activity found in stains from laboratory casework based on both the amylase concentration and the elapsed time between collection and analysis. The evidential value of the presence or absence of amylase activity in casework stains is also discussed.