Application of MALDI-TOF MS for Estimating the Postmortem Interval in Rat Muscle Samples

Area of Science:

• Forensic Science
• Biochemistry
• Analytical Chemistry

Background:

• Accurate postmortem interval (PMI) estimation is vital in forensic investigations.
• Current PMI estimation methods face challenges in accuracy and reliability.
• Molecular changes in tissues after death offer potential biomarkers for PMI determination.

Purpose of the Study:

• To evaluate the utility of MALDI-TOF MS for estimating the postmortem interval (PMI).
• To identify specific molecular markers indicative of postmortem changes in muscle tissue.
• To develop a predictive model for PMI estimation using mass spectrometry data.

Main Methods:

• Muscle samples were collected from Sprague Dawley rats at 0, 48, 96, and 144 hours postmortem.
• Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was employed to analyze molecular profiles.
• Principal component analysis (PCA) was used to analyze spectral data and differentiate time groups.

Main Results:

• Specific peaks (m/z 1511, 1543, 1564, 1586) showed a clear decrease in intensity over the 144-hour postmortem period.
• Principal component analysis effectively separated samples based on postmortem time intervals.
• The developed prediction model demonstrated high recognition (95.93%) and cross-validation (83.72%) accuracy.

Conclusions:

• MALDI-TOF MS can effectively detect molecular alterations in muscle tissue postmortem.
• These molecular changes correlate with the postmortem interval.
• MALDI-TOF MS is a viable technique for accurate postmortem interval estimation in forensic science.