Evaluation of Isoheme: A Novel Replacement for Blood in Forensic Science

Overview

Animal blood is used to create bloodstains for forensic science training and analysis. Blood is expensive, perishable and poses a safety hazard which limits its use by trainers and rules out its use by teachers. There is a need for a replacement that forms stains like blood without the issues of using blood. The purpose of this study was to evaluate the properties of a novel blood replacement designed to meet forensic science needs. Isoheme was formulated with food grade ingredients to mimic the viscosity, density and surface tension of blood. When Isoheme ($0.25 for 50 mL) and porcine blood ($45 for 50 mL) drops were released from 60 cm and 100 cm and collected at 90° on cardstock, the diameters and numbers of spines/scallops of the Isoheme stains were not significantly different from the bloodstains. When the drops were released from 100 cm and collected on cardstock, foam core, ceramic tile and vinyl tile the diameters of the Isoheme stains at 90° and the calculated impact angles at 30° also were not significantly different. Tests confirmed Isoheme is stable for at least 24 weeks. When Isoheme and porcine blood spatter were collected at 50 cm, the calculated distance to the point of origin was underestimated by 10% for Isoheme versus 24% for blood. Isoheme also worked well as a teaching tool for high school forensic science classes. This study confirmed that Isoheme is a safe, affordable, easy to use, stable blood substitute that meets forensic science needs.