Isolation of epithelial cells from tooth brush and gender identification by amplification of SRY gene

INTRODUCTION: This study determines the importance of tooth brush from which DNA can be isolated and used for sex determination in forensic analysis. MATERIALS AND METHODS: A total of 30 samples were collected and stored at room temperature for different periods of time interval. The epithelial cells adhered to the bristles of tooth brush were collected and genomic DNA was extracted and quantified using Nanodrop 1000 spectrophotometer. RESULTS: Gender identification was done by amplification of sex determining region on Y chromosome (SRY) gene using real-time polymerase chain reaction and minimal amount of DNA (in pico grams) with 100% sensitivity and 73.3% specificity, i.e., all male samples showed positive results and out of 15 female samples 4 showed false positive results, i.e wrongly identified as males. CONCLUSION: With this study, we conclude that PCR is a valuable and sensitive procedure where minute contamination may cause alteration in the result, i.e, 4 females showed false positive result. Minute amount of DNA in picograms, which was collected at different intervals is enough for amplification of SRY gene and tooth brush can be used as one of the very valuable sources of gender identification.