1Department of Forensic Science, SGT University, Gurgaon, Haryana, India
2Department of Forensic Medicine & Science, SGT University, Gurgaon, Haryana, India
3Department of Mathematics, SGT University, Gurgaon, Haryana, India
4Department of Audiology & Speech-Language Pathology, Amity UniversityGurgaon, Haryana, India
5Department of Biology & DNA Profiling, Central Forensic Science Lab, Central Bureau of Investigation, New Delhi, India
6Department of Biology & DNA Profiling, Central Forensic Science Lab, Central Bureau of Investigation, New Delhi, India
*Corresponding Author: Dr. Leena Kumari, PhD Scholar, Department of Forensic Science, SGT University, Gurgaon, Haryana, India Contact: +91 99583-58380 Email: leena.bhardwaj2000@gmail.com
Introduction: Although role of teeth as a substrate for forensic investigation is established since long time, the relationship between the status of extracted tooth and DNA yield has not been clearly established. Thus, the primary objective of this study was to estimate the quality and quantity of DNA in mild to moderate carries teeth samples and compare it with freshly extracted control teeth using Real Time-Polymerase Chain Reaction (RT-PCR) and subsequent multiplex STR typing.
Method: A total of 40 teeth, mild to moderately caries tooth (Twenty) and freshly extracted normal teeth (Twenty) were randomly collected. Isolation and extraction of DNA was done by organic extraction method. Precipitation of samples was done using 100% chilled ethyl alcohol followed by concentration and washing of DNA via column based technique using DNA binding buffer and DNA wash buffer. Agarose gel electrophoresis was done to roughly estimate the DNA content while exact quantity of DNA was estimated by RT-PCR technique. Short Tandem Repeat (STR) profiling was done for generation of DNA profile including sex determination by identification of amelogenin gene.
Result: Independent sample t test analysis revealed that the mean quantity of DNA (in pg/l) was significantly higher in freshly extracted (M=29.91, SD=0.65) than mild to moderate carious (M=9.71, SD=0.45), t(38)=114.19, p<0.000. Similarly, quality of DNA was analyzed using smear quality and it was obtained that the quality of DNA of freshly extracted teeth (M=4.55, SD=0.51) was significantly higher that the mild to moderate carious (M=2.55, SD=0.6), t(38)=11.3, p<0.000.
Conclusion: Despite, the significant quantitative and qualitative loss of DNA in carries tooth, DNA profiles with adequate resolution of the autosomal markers and amelogenin marker were observed in present study valuable for human identification and the gender identification leading to individualization was facilitated.
Abbreviations: Phenol Cholroform Isoamylalcohol(PCI), Short Tandem Repeat(STR), Real Time Polymerase chain reaction (RT-PCR)
Amelogenin, DNA, Hydroxyapetite, Gender Identification, Electrophoresis, Forensic Investigation
