Identifying individuals at crime or mass disaster scenes can pose numerous problems for the investigators. Age determination can be a very useful tool in aiding to correctly identifying bodies, partial remains or biological fluids found at these types of scenes, by providing investigative leads. Traditional methods used by forensic anthropologists, such as morphological inspections, are often more time consuming, less precise and limited to cases with skeletal remains.
Advances in epigenetics research have shown a linear correlation between age and the amount of DNA methylation at certain genetic loci. This modification predominantly occurs at the 5′ carbon on cytosine molecules when trailed by guanine (CpG site), leading to 5-methylcytosine. This gradual modification during an individual’s lifespan has enabled accurate age prediction. Pyrosequencing can detect and quantify the slightest change in these methylation levels, providing age estimations that correlate very closely with chronological age.
Over the past several years, Pyrosequencing has made considerable impact and growth as an age predictor in forensic research, thus allowing DNA methylation to become a more established and informative method to consider. The Central Forensic Laboratory of the Police (CFLP) in Warsaw have previously implemented age determination using the PyroMark Q24 platform. With the recent development of the PyroMark Q48 Autoprep, a newer version with a fully automated protocol, the CFLP performed an internal validation to compare the two instruments.
The innovative design of the PyroMark Q48 Autoprep allows for double the throughput while optimizing performance and functionality. Advanced chemistry and algorithms reduce background noise while increasing read length and reliability. In addition, there is minimal manual interaction due to the fully automated template preparation integrated into the protocol.
This application note discusses the validation of the PyroMark Q48 Autoprep by comparing the PyroMark Q48 Autoprep to the PyroMark Q24 platform to demonstrate that the same age prediction algorithm is suitable without modification. This study uses the same starting material, genomic DNA extracted from the blood, as in the original validation for the PyroMark Q24. These blood samples ranged in donor age and were stored appropriately for a little over one year. After the genetic material was bisulfite converted, specific markers were amplified and Pyrosequencing was used to determine their methylation level. Read more!