Combination of Autosomal and Y-STR Analysis, an Alternative to Differential Extraction: A Case Study
Journal: International Journal of Forensic Science & Pathology (IJFP) (Vol.09, No. 01)Publication Date: 2022-01-24
Authors : Sandip Ghosh Sutanwi Bhuiya Bipradut Sil;
Page : 468-474
Keywords : ;
Abstract
The samples from the sexual assault cases are often found as a imbalanced mixture of epithelial cells of victim and accused sperms, with an excess of victim's material resulting in an unfavorable ratio of male to female. As the male-DNA contribution is much lower than the female epithelial cell population in gynecological sample, analysis and interpretation of the individual contributions, has always been a challenge for the forensic scientists. Various techniques have been tried to separate the male DNA from the female part, including Differential Extraction (DE), but none of those are cost effective and time saving. The Y-STR haplo-typing, has been used for the mixed sample where the autosomal STR failed to produce visible peaks for the male DNA. In those cases combined autosomal and Y-STR analysis provided additional leads for the investigation. Here we report one case, where we conducted both autosomal-STR and Y-STR analysis, in combination, from the gynecological mixture sample, completely avoiding the complex ‘Differential Extraction'. The male to female contribution ratio in a gynecological sample, was found to be 1: 3.39 as deduced by the real-time qPCR using QuantiFilerTM Trio kit. As the mixed autosomal profile included both the suspect and the victim , using the qualitative and semi-quantitative binary model of interpretation, the Y-STR analysis confirmed the offender. This method is applicable when a preliminary suspect list is available to the investigative agency to compare with. Since this method is simple and is not influenced either by the azoospermic and vasectomized male samples or mixed samples other than semen viz. male DNA under fingernails of the victim, male touch DNA on the skin of the victim, and the clothing or belongings of a female victim, we propose this combination method may be highly effective in resolving a broad spectrum of cases in the Forensic laboratory.
Other Latest Articles
- Combination of Autosomal and Y-STR Analysis, an Alternative to Differential Extraction: A Case Study
- WEB BASED RESOURCES AND TOOLS IN ONLINE LEARNING: A PARTICIPATORY AND COLLABORATIVE METHOD TO ENHANCE READING AND WRITING SKILLS IN THE STUDENTS STUDYING INTERMEDIATE COURSE OF ANDHRA PRADESH AND TELANGANA STATES
- COMPARATIVE EVALUATION OF THE DIGITAL MARKETING PROCESS TO IMPROVE REVENUE AND CONVERSION RATES THROUGH REAL-TIME INTERACTIONS WITH SPECIFIC AUDIENCES
- DYNAMIC REGRESSION APPROACH TO IDENTIFYING THE DETERMINANTS OF INWARD FOREIGN DIRECT INVESTMENT FOR INDIA
- GLOBALIZATION OR DE-GLOBALIZATION – THE WAY FORWARD FOR INDIA POST COVID 19 PANDEMIC
Last modified: 2022-02-24 19:59:47