Forensic Applications of Fluorescent Microscopy Image Credit: Micha Weber / Shutterstock.com How is microscopy used in forensics? A forensic investigation on determining the cause of death often depends upon the analysis of the evidence of the time since death, otherwise known as the postmortem interval (PMI). While several macroscopic observations can be utilized to determine the PMI, microscopy techniques, particularly electron microscopy (EM), can provide more accurate PMI estimates. For example, EM has successfully been used to study morphological alterations in human nerves to assess what stage of myelin degradation has occurred. Several subtypes of EM like transmission electron microscopy (TEM) have also been used to provide information on the cause of death. More specifically, TEM has been used to detect ultrastructural changes in the myocardium and study alterations in skin morphology and mentalization that resulted from suspected cases of electrocution.