Validation of the fluorescence-based Sperm Hy-Liter™ kit as a means to standardize spermatozoa identification in sexual assault cases

To enhance searching and standardize the identification of spermatozoa in sexual assault exhibits, the Sperm Hy-Liter™ kit was evaluated and validated using a large number of sexual assault type specimens and 6mm circle slides. The practicality and sensitivity of the fluorescence-based protocol were compared to our current phase contrast microscopy protocol and examined in the context of an improved workflow for processing sexual assault cases. Experiments performed indicate that the Sperm Hy-Liter™ assay is (1) highly specific and valid (no interference from semen obtained from various animals and absence of positive fluorescence signals in all control slides prepared from swabs with only blood, yeast, urine, vaginal epithelial cells or fecal material), (2) sensitive and reliable (spermatozoa detected in vaginal swabs soaked in 1:1000 and 1:10,000 semen dilutions; spermatozoa detected more effectively in real casework samples containing few spermatozoa compared to phase contrast microscopy), (3) fast (1min versus average of 10min or more using phase contrast microscopy for