Assessment of DNA degradation patterns in biological material is of great significance. The assays could be useful in the estimation of post mortem interval (PMI) or in evaluation of tissue preservation media. Using the current available methods estimation of PMIs from weeks to years, where soft tissues are depleted and where morphological methods cannot be applied, are more challenging.

Some studies have suggested the feasibility of using DNA fragmentation patterns in the intermediate intervals after death for estimation of PMI.

This study aims at development and evaluation of analytical methods for assessment of DNA degradation and application of such methods on human rib bone samples taken freshly after death and stored for different lengths of time in different environmental conditions for estimation of time since death. Radioisotope based techniques as well as more sensitive real-time and ordinary polymerization chain reactions (PCR) have been engineered to amplify different fragments of human DNA for quantitative analysis.

Our investigations have shown promising results in feasibility of using mitochondrial DNA templates in quantitative assessment of DNA degradation and for analysis of highly degraded post mortem samples.

This study establishes that the extent of degradation significantly affects the ratio of intact short to long DNA fragments in genomic and mitochondrial DNA in artificially degraded samples.

Furthermore the results indicate the significance of the environmental conditions such as temperature and humidity on DNA preservation. Humid environments presented the superior condition for degradation of DNA, leading to massive depletion of rib bone DNA in a few weeks.