Determination of the early time of death by computerized image analysis of DNA degradation: Which is the best quantitative indicator of DNA degradation?

Abstract

This study evaluated the correlation between DNA degradation of the splenic lymphocytes and the early time of death, examined the early time of death by computerized image analysis technique (CIAT) and identified the best parameter that quantitatively reflects the DNA degradation. The spleen tissues from 34 SD rats were collected, subjected to cell smearing every 2 h within the first 36 h after death, stained by Feulgen-Van's staining, three indices reflecting DNA content in splenic lymphocytes, including integral optical density (IOD), average optical density (AOD), average gray scale (AG) were measured by the image analysis. Our results showed that IOD and AOD decreased and AG increased over time within the first 36 h. A stepwise linear regression analysis showed that only AG was fitted. A correlation between the postmortem interval (PMI) and AG was identified and the corresponding regression equation was obtained. Our study suggests that CIAT is a useful and promising tool for the estimation of early PMI with good objectivity and reproducibility, and AG is a more effective and better quantitative indicator for the estimation of PMI within the first 36 h after death in rats.

Profiling of RNA Degradation for Estimation of Post Morterm Interval

“…This definition seems to fit well in post mortem degradation of nucleic acids [6]. Indeed, with the advances of molecular biology, the analysis of time-dependent degradation of nucleic acids (both DNA and RNA) became a focus of attention in clinical medicine as well as in forensic science [6], [7]. In this context, the RNA potential has been studied for several purposes, namely the identification of body fluids [8], [9], [10], time-dependent expression of troponin I mRNA in the contused skeletal muscle as a possible marker for wound age estimation [11], [12], and post mortem assessment of the functional status of cells and organs aiming the diagnosis of cause and mechanism of death [13].…”

“…This definition seems to fit well in post mortem degradation of nucleic acids [6]. Indeed, with the advances of molecular biology, the analysis of time-dependent degradation of nucleic acids (both DNA and RNA) became a focus of attention in clinical medicine as well as in forensic science [6], [7].…”

Cell death proteins as markers of early postmortem interval

“…as a consequence, there is a release and damage of cellular components and metabolites. Few reports have analyzed changes associated with the time since death within the first hours of death [20][21][22][23].…”

Image analysis on corneal opacity: A novel method to estimate postmortem interval in rabbits

“…With the rapid development of computer technology, the image analysis technique (IAT) and related equipment (image analysis system, IAS) have been extensively used in many fields [30][31][32][33] .…”