The Center for Human Identification (CHI) is currently helping with the development of two technologies associated with mtDNA typing that expand the testing coverage of the human mitochondrial genome from 600 base pairs in the control region to the entire genome (16,569 bps). This is very important for helping to differentiate common human mitochondrial profiles. The research is being facilitated using chip technology supplied by Affymetrix and a re-sequencing system developed by Applied BioSystems (ABI). Recently, the re-sequencing system was successfully alpha tested by our facility.
CHI is continuing the evaluation and testing of "mini-STR" systems for the identification of human remains. Mini-STR systems are designed to target smaller fragments of DNA. The more degraded the sample, the smaller the fragments. This technology allows one to identify the alleles (identification markers) found in these smaller fragments. CHI aided in the pre-evaluation of ABI's first commercially available kit. Our facility has begun the evaluation and testing process of a second kit that expands the range of markers available for familial testing.
Extraction Procedures for Optimal Bone DNA Recovery
CHI is also involved in research designed to help recover DNA from old and degraded skeletal remains. Research is being conducted for evaluating different bone extraction protocols needed to develop an optimal bone DNA recovering system. The end result will be extraction procedures that yield more nuclear and mitochondrial DNA needed for identification.
DNA Repair Cocktails
A research project for creating DNA repair cocktails, in conjunction with New England Biolabs, has been submitted to the National Institute of Justice (NIJ). CHI will evaluate multiple enzyme cocktails that will aid in the repair and restoration of degraded and damaged DNA samples. Many skeletal remains samples have been exposed to years of harsh environmental conditions resulting in degraded DNA. Once samples have been taken through the repair process, they can then be taken through the amplification and sequencing stages rendering full DNA profiles. This research could eventually provide a DNA recovery method for the identification of severely degraded and damaged remains samples.
Expert Systems Software Evaluation
CHI is in the process of evaluating an "Expert System" that was initially developed by the University of Tennessee. This is an automated software application that reviews DNA STR and Sequence data. The expert system will replace the required "second read" by a qualified analyst. The system will automatically evaluate DNA sequences and pass only those that meet all of the required set standards and flag those that do not. Those samples that fail will then be subjected to a manual second read by a qualified analyst. Those that pass continue through the administrative review and ultimately are entered into the FBI's CODIS system. This system is designed to dramatically improve sample turn-around times.