Application of Immunohistochemistry in Estimating the Post Mortem Interval

Description

Estimation of the post mortem interval is essential in forensic science and is constantly investigated in search of reliable, accurate and most importantly applicable methods.
Few studies have investigated the application of immunohistochemistry in forensic cases for determining time since death. Former research suggests that protein denaturization increases with increasing post mortem intervals causing less efficient stainability.
This study explored the use of immunohistochemistry through microscopical and digital evaluation on tissue from 15 cases with known post mortem intervals ranging from 0–1 to 7–8 days.
Decreasing intensities were expected with increasing post mortem interval. Brain, liver and lung tissue were all stained with antibodies targeting CKAE, S-100, Vimentin and CD45 showing varying immunoreaction depending on tissue and antibody combination. Staining signal was evaluated microscopically and graded positive, fading or negative. Using digital analysis software ImageJ, slides were digitally evaluated and mean grayscale values were measured as expression of staining intensity.
No overall correlation could be detected between increasing post mortem interval and transition of staining signalling from positive to negative. Neither was the case for increasing post mortem interval and staining intensities. Variability of staining in each case was investigated looking at the distribution of coefficient of variation for each case, however no consistent pattern was prevalent.
Our results did point towards some non- significant trends, which could not be explained by increasing post mortem interval alone. Future research must take factors affecting tissue decomposition into consideration when assessing immunohistochemistry as tool for post mortem interval estimation.

Period	1. Nov 2019
Event title	Dansk Selskab for Retsmedicins Årsmøde 2019
Event type	Conference
Location	Odense, DenmarkShow on map