Evaluation of DNA degradation using flow cytometry: promising tool for postmortem interval determination
Teddric Williams1, Shivani Soni, Jason White
1From the Alabama State University, Montgomery, AL.
Abstract:
Over the years, there have been numerous formulas proposed for use in determining the postmortem interval (PMI); however, no method is all encompassing and absolute. Even so, very little research has been undertaken to determine if there is a viable correlation between the rate of DNA degradation and PMI, which can be calculated from analysis by flow cytometry. In this study, we analyzed the rate of DNA degradation of spleen and brain tissues from 15 cadavers over a 96-hour period of time at 2 temperature conditions, that is, 21°C (room temperature) and 4°C (refrigerator) to mimic summer and winter weather, respectively. The resulting data were used to form a pattern that correlates DNA degradation to cell death occurrence. Statistical analyses were performed to determine the significance of the relationship between PMI and DNA degradation. Moreover, in search of alternative reliable organs of interest for PMI estimation, the results demonstrate that the brain has lesser DNA degradation as compared with the spleen. Thus, the current study suggests that the brain can be an organ of choice for PMI studies, but more research is underway in this aspect.
Insights
Researchers explored DNA degradation in spleen and brain tissues to estimate postmortem interval (PMI). The brain showed less DNA degradation than the spleen, suggesting its potential for PMI determination.
Area of Science:
- Forensic Science
- Molecular Biology
- Biochemistry
Background:
- Accurate postmortem interval (PMI) estimation is crucial in forensic investigations.
- Existing PMI methods have limitations, necessitating novel approaches.
- The correlation between DNA degradation and PMI requires further investigation.
Purpose of the Study:
- To investigate the relationship between DNA degradation rates and PMI using flow cytometry.
- To evaluate spleen and brain tissues as potential indicators for PMI estimation.
- To assess the influence of temperature on DNA degradation patterns.
Main Methods:
- Analysis of DNA degradation in spleen and brain tissues from 15 cadavers over 96 hours.
- Incubation of tissues at two temperatures: 21°C (room temperature) and 4°C (refrigeration).
- Utilizing flow cytometry for quantitative DNA degradation analysis and statistical significance testing.
Main Results:
- Established a correlation pattern between DNA degradation and cell death occurrence over time.
- Demonstrated significantly less DNA degradation in brain tissue compared to spleen tissue.
- Observed distinct DNA degradation rates influenced by environmental temperature conditions.
Conclusions:
- The brain exhibits lower DNA degradation, making it a promising organ for PMI estimation.
- DNA degradation analysis via flow cytometry offers a viable method for PMI determination.
- Further research is warranted to validate the brain's utility in diverse PMI scenarios.
