NCJ Number
138360
Journal
Journal of the Forensic Science Society Volume: 32 Issue: 2 Dated: (April/June 1992) Pages: 101-115
Date Published
1992
Length
15 pages
Annotation
This investigation showed that when blood or serum was derived from more than one individual and mixed, misinterpretation of blood grouping results could occur.
Abstract
The isoenzymes erythrocyte acid phosphatase (EAP) and phosphoglucomutase (PGM) were typed in mixed red cell samples that had been derived from two individuals. The protein group- specific component (GC) was typed in mixed serum samples. Typing was performed by isoelectric focusing on ultrathin polyacryalamide gels. Depending on the mixture, from 2 to 20 percent by volume of a second blood or serum needed to be present in a mixture before it could be detected. Blood was easily identified as a mixture when PGM or GC isoelectric focusing results consisted of band patterns with extra bands, when bands were present in unusual proportions, or when EAP results had unusual band intensities. The appearance of these features in the grouping of case work bloodstains might indicate that the stain contained blood from more than one source. In a few instances, blood or serum could not be identified as a mixture when masking effects occurred or when the mixture produced a combined, apparently normal, pattern. An appendix contains supplemental data on PGM, EAP, and GC grouping results. 4 references, 2 tables, and 8 figures