Alternative direct-to-amplification sperm cell lysis techniques for sexual assault sample processing.
J Forensic Sci
; 67(4): 1668-1678, 2022 Jul.
Article
em En
| MEDLINE
| ID: mdl-35285573
ABSTRACT
The prevalence of sexual assault cases and increasingly sensitive DNA analysis methods have resulted in sexual assault kit backlogs in the United States. Although traditional DNA extraction and purification utilizing detergents, proteinase K, and DTT have been the primary technique for lysing sperm cell fractions from these samples, it is labor-intensive and inefficient regarding time and sperm DNA recovery - hindering the ability of forensic analysts to keep pace with evidence submissions. Thus, this study examined seven alternative sperm cell lysis techniques to develop a method that could efficiently lyse sperm and consistently generate high-quality profiles while also reducing time, labor, and cost requirements. Microscopic examination of lysates indicated only Casework Direct and alkaline techniques could lyse all spermatozoa within samples, while quantification results demonstrated all methods performed comparably to the control method of forensicGEM™ Sperm (p > 0.06). Amplification with 0.25 ng DNA revealed that unpurified lysates from Casework Direct, alkaline, and NP-40 techniques produced DNA profiles with acceptable mean STR peak heights and interlocus balance, both of which were similar to or better than the control. Overall, this study demonstrated the ability of Casework Direct, alkaline, and NP-40 methods to efficiently lyse spermatozoa and provide high-quality STR profiles despite the absence of a purification step. Ultimately, based on the data reported herein, alkaline lysis is the recommended alternative sperm lysis approach given its ability to generate high-quality profiles, save time, and decrease the cost per reaction when compared to traditional sperm cell lysis methods.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sêmen
/
Delitos Sexuais
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
/
Male
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article