DNA HASIL EKSTRAKSI DARI BERCAK SPERMA PADA KAIN KATUN DAN POLIESTER YANG DISIMPAN HINGGA 40 HARI

Abstract

DNA is an important evidence in forensic-based investigation which is useful in the process of solving criminal cases. Rape is an act of crime which could leave evidence such as sperm stain on fabric. The said stain can be processed to obtain the perpetrator’s DNA and uncover their identity. This study aims to determine whether DNA from sperm stains on cotton and polyester fabrics which had been stored for 0, 20, and 40 days could be extracted and to determine the quality and quantity of the extracted DNA. This study conducted from September to December 2020 at the Serology and Molecular Forensics of UPT Laboratory and the Integrated Biomedical Laboratory of Udayana University. The research method consisted of sample preparation, DNA extraction using Chelex 100 resin, and DNA quantification and qualification using NanoDrop. Data from DNA quantity are analyzed using two-way ANOVA and chi-squared test method. Results of this study shows that DNA can be extracted from sperm stains on cotton and polyester fabrics which are stored for up to 40 days. The decrease of DNA quality and quantity in all samples directly proportional to the increase of the storage time treatment. The decrease of DNA quantity on cotton fabric occurs by 80.42% (fresh-0 day), 12.02% (0 day-20 days), and 0.78% (20 days-40 days). Decrease of DNA quantity on polyester fabric occurs by 62.16% (fresh-0 day), 11.40% (0 day-20 days), and 8.47% (20 days-40 days). Statistical analysis on the quantity of DNA showed that the rate of reduction in DNA concentration was influenced by the type of cloth used.