Modified Differential Extraction Protocol for the Identification of Suspect: A Case of Sexual Assault
DOI:
https://doi.org/10.48165/jiafm.2024.46.2.21Keywords:
Sexual assault, Differential extraction, Spermic fraction, Non-spermic fractionAbstract
DNA fingerprinting is a standard recognized technology for individualization of suspect in criminal justice system. The identification of male contributors from high female and low male ratios through different body fluid mix's is still a major issue to address in forensic DNA laboratories. Traditional methods of separation of the male-female fraction are time-consuming and labour intensive and might give variable results. Currently, there remains scope to refine the method of differential extraction for better results. In the present case study, differential extraction was modified and it was noted that total male DNA yield was 1.561 ng/µl and 2.675 ng/µl in the spermic fraction of the vaginal slide and underwear of the victim, respectively. Although the underwear of the suspect contains female DNA in the non- spermic fraction was 7.864 ng/µl from the underwear of the suspect. Therefore, complete autosomal STR DNA profile of suspect was obtained from the victim vaginal slide and underwear due to significantly reducing the excessive quantity of female DNA using modified differential DNA extraction process. Thus, a modified method is recommended for a better male autosomal STR DNA profile in sexual assault cases.
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