Human Blood Typing: A Forensic Science Approach Part I: Background Lawrence Kobilinsky' and Francls X. Sheehan John Jay College of Criminal Justice, 445 West 59th Street, New York, NY 10019 In a previous article published in the Journal of Chemical Educotim, we described the forensic scientist's approach to identifying a suhstance as human blood ( 1 1 . The techniques described included the presumptive catalytic tests and the confirmatory crystal tests that together allow for the conclusion that the suhstance in question is indeed blood. We also described the serologically based Ouchteriony test, which indicates whether blood is human or nonhuman. This article outlines the forensic methods used in "ty. ping" human blood, which as physical evidence is often found in the dried state. These techniques differ from those commonly used by the clinicalserologi& who analyze liquid blood. The experiments discussed herein can be used to instruct chemistry and biochemistry students at the senior high school and colleee undereraduate levels. In fact. these experiments have Geen con&cted at the high schooilevel in an elective forensic science course and have been found to be informative as well as suitable. The subject of antigen-antibodv reactions is an i m ~ o r t a n one t for chemistrv and biochemistry students, who may use such fundamental immunochemical techniques as radioimmunoassav, enzyme immunoassay, and
