Sexual assault kit backlogs remain a persistent problem in forensic laboratories worldwide. Processing individual items, separating sperm and non-sperm cell fractions, extracting both, producing clean STR profiles are labour-intensive and time-consuming, even with automation.

A 2024 paper in Forensic Sciences Research (Hudson and Dawson Green, Virginia Commonwealth University) tested a combined enzymatic and alkaline approach to differential cell lysis, with the goal of producing a faster, more efficient method for separating contributor fractions in sexual assault evidence.

The method used forensicGEM chemistry for the epithelial cell lysis step, followed by a sodium hydroxide treatment to complete sperm cell lysis. The full workflow completed in 25 minutes from swab to lysed fractions.

The results: sperm fraction STR profiles showed a mean male-to-female DNA ratio of 1.74:1 - a 3.01-fold improvement over unseparated controls. On average, 5.9 additional male alleles per sample were detected in the sperm fraction that were not identifiable in the unseparated material.

The authors note that further optimisation of the non-sperm lysis step is warranted and identify inhibition in some conditions as an area for future work. This is an honest assessment of where the method currently stands: a validated proof of concept with clear performance data and a defined direction for further development.