Epithelial cell fraction
Definition
The non-sperm cellular material in a sexual assault sample. Contains skin and mucosal cells from both victim and any perpetrator who made contact. The target for profiling when spermatozoa are absent.
Related terms
- Azoospermia
- The absence of spermatozoa in ejaculate, whether due to obstructive causes (post-vasectomy) or non-obstructive causes (spermatogenic failure). Affects roughly 1% of men...
- Differential extraction
- A DNA extraction method used for sexual assault evidence that separates sperm cells from epithelial cells before cell lysis, yielding two DNA...
- Double-swab technique
- DNA collection method in which a wet swab is applied to the wound perimeter first to rehydrate and collect biological material, followed...
- Timing window
- The period after an assault during which a specific locus is likely to yield viable foreign DNA. Windows vary substantially by locus:...
- Y-STR analysis
- Short tandem repeat profiling targeting the male-specific Y chromosome. Used when female victim DNA overwhelms the autosomal profile in a mixture, allowing...
Explained in
- Swabbing Technique and DNA YieldThe non-sperm cellular material in a sexual assault sample. Contains skin and mucosal cells from both victim and any perpetrator who made contact. The target f...