This study provides a comparative analysis of DNA contamination, degradation, and damage via sequencing and electrophoresis.
This project, funded by a grant from the National Institute of Justice (NIJ), evaluated whether DNA contamination can mimic the characteristics of low copy number (LCN), aged, damaged, and degraded DNA samples. Researchers used Massive Parallel/Next Generation Sequencing to see if specific patterns of nucleotide damage are present with surface DNA contamination that has been aged and/or exposed to varying concentrations of sodium hypochlorite (bleach) and UV. The proposed project was divided into two phases. Phase 1 involves understanding the process and rate of degradation and damage of applied touch DNA contamination on human skeletal remains and evidence tape. Five time intervals (ranging from 0 days to 1 year), three bleach treatments and three UV treatments were tested. Two additional handlers (cumulative) created a scenario of minor contributors often encountered in forensic scenarios. Phase 2 involves understanding the utility and degradation of the skin microbiome associated with touch DNA. This included determining if unique forensic signatures can be identified and compared, especially on bone substrates that may have their own microbiome signature.