Sensitive, rapid and cost effective approach for the estimation of time elapsed after death using human cardiac troponin i

Estimation of postmortem interval is critical in forensic investigations related to homicides, suicides and accidents. The aim of the present investigation was to develop a simple and cost effective method to estimate the time since death based on the degradation of a protein, cardiac Troponin I (cTnI), which is a part of a troponin complex responsible for calcium dependent muscle contraction. A simple and efficient extraction protocol to analyze the banding pattern of cTnI in postmortem tissue was developed. The analysis involves extraction of the protein and separation by SDS-PAGE. Human cardiac tissue was used to develop and optimize the protocol of banding profile. The results show a characteristic banding pattern of cTnI of human cadaver’s heart tissue. The degradation band pattern of standards of human cardiac tissues of known time since death are compared with the degradation band pattern of the unknown samples in a simple comparative analysis to predict the actual time since death. The human heart degradation-banding pattern of tissue cTnI is useful in the determination of time since death up to 5 days. Overall, this technique offers advantages such a wide postmortem interval, measurable degradation pattern, cost effectiveness and is sensitive enough to be used to estimate the postmortem interval.