A Comparison Study of Cryopreservation of Seminal Fluid between Flinders Technology Associates (FTA-card) and Swab for Multiplex Short Tandem Repeats (STR) Analysis

Dhuha Salim  Namaa; Thooalnoon Younes  Al-Janabi; Halah Khalid Ibrahim  Al-Sammarraie; Asia Abd-Alatief  Mahdi; Haider K.  AL-Rubai

doi:10.24996/ijs.2024.65.7.%g

Authors

Dhuha Salim Namaa Forensic DNA Center for Research and Training, Al-Nahrain University, Jadriya, Baghdad, Iraq
Thooalnoon Younes Al-Janabi Forensic DNA Center for Research and Training, Al-Nahrain University, Jadriya, Baghdad, Iraq
Halah Khalid Ibrahim Al-Sammarraie Forensic DNA Center for Research and Training, Al-Nahrain University, Jadriya, Baghdad, Iraq https://orcid.org/0000-0002-8305-3540
Asia Abd-Alatief Mahdi Forensic DNA Center for Research and Training, Al-Nahrain University, Jadriya, Baghdad, Iraq
Haider K. AL-Rubai Forensic DNA Center for Research and Training, Al-Nahrain University, Jadriya, Baghdad, Iraq

DOI:

https://doi.org/10.24996/ijs.2024.65.7.%25g

Keywords:

Sperm cryopreservation, Flinders Technology Associates FTA cards, DNA extraction, Short tandem repeats (STR) analysis

Abstract

Background Whatman™ FTA (Flinders Technology Associates) is a form of card soaked in chemicals that denatures proteins while protecting DNA and ensuring the safe handling of dried body fluid spots (blood, semen, and saliva) and buccal cells. To this day, these cards are still infrequently used in forensic science. Therefore, reference samples including biological material may be collected on FTA cards for genetic analysis that have been widely used for DNA preservation and analysis, particularly in forensic sciences and genetic studies. The goal of the study was to evaluate the effects of cryopreservation on DNA quantitative and short tandem repeats (STR) profiling by comparing the yield and quality of DNA extracted before and after cryopreservation using FTA card and swabs in the forensic analysis. The mean total DNA concentration and the purity of seminal fluid from FTA-cards and swabs before and after sperm cryopreservation were measured by using nano-drop spectrophotometer (93.688 ± 12.5) (90.94 ± 13.9) ng/ µl; ( 221.07 ± 20.97)( 135.47 ± 19.6) ng/ µl respectively. Also a highly significant difference (p<0.001) was detected when the results of concentration DNA on FTA card were compared with dilution using wash media before and after sperm cryopreservation. Whereas significant difference (p<0.05) was observed between DNA concentration on FTA card with and without dilution after sperm cryopreservation. STR loci were present in the majority of data, particularly in FTA-card and swab samples where results explained that 100% of STR profiles were present in all 15 loci, both before and after sperm cryopreservation. In contrast to the conventional method of storing and analyzing STR profiling, it can be concluded that seminal fluid samples taken by FTA card and swabs can be taken and stored for a time by cryopreservation, leads to maintaining DNA integration in the field of criminal research.