title: An Optimized Centrifugal Method for Separation of Semen from Superabsorbent Polymers for Forensic Analysis.
abstract: Connection of a perpetrator to a sexual assault is best performed through the confirmed presence of semen, thereby proving sexual contact. Evidentiary items can include sanitary napkins or diapers containing superabsorbent polymers (SAPs), complicating spermatozoa visualization and DNA analysis. In this report, we evaluated the impact of SAPS on the current forensic DNA workflow, developing an efficient centrifugal protocol for separating spermatozoa from SAP material. The optimized filtration method was compared to common practices of excising the top layer only, resulting in significantly higher sperm yields when a core sample of the substrate was taken. Direct isolation of the SAP-containing materials without filtering resulted in 20% sample failure; additionally, SAP material was observed in the final eluted DNA samples, causing physical interference. Thus, use of the described centrifugal-filtering method is a simple preliminary step that improves spermatozoa visualization and enables more consistent DNA yields, while also avoiding SAP interference.
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284.
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Camarena
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284.
authors.forename: Bailey K
authors.initials: BK
authors.lastname: Glasscock
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284.
authors.forename: Demi
authors.initials: D
authors.lastname: Daniels
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284.
authors.forename: Nicolle
authors.initials: N
authors.lastname: Ackley
authors.affiliation: San Diego Police Department, 1401 Broadway, San Diego, CA, 92101.
authors.forename: Marybeth
authors.initials: M
authors.lastname: Sciarretta
authors.affiliation: Department of Forensic Science, Virginia Commonwealth University, 1015 Floyd Avenue, Richmond, VA, 23284.
authors.forename: Sarah J
authors.identifier: http://orcid.org/0000-0003-0093-8261
authors.initials: SJ
authors.lastname: Seashols-Williams
mesh_terms: D002498:Centrifugation; D004247:DNA / Q000032:analysis; D041382:Diapers, Adult; D041381:Diapers, Infant; D053566:Hygiene Products; D005374:Filtration; D005554:Forensic Medicine / Q000379:methods*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D011108:Polymers; D013094:Spermatozoa / Q000737:chemistry*
chemical_list: D004247:DNA; D053566:Hygiene Products; D011108:Polymers
keywords: 
  DNA
  ; diapers; forensic science; sanitary napkins; seminal fluid; sexual assault; spermatozoa; superabsorbent polymers