NCJ Number
225056
Journal
Forensic Science International: Genetics Volume: 2 Issue: 4 Dated: September 2008 Pages: 363-371
Date Published
September 2008
Length
9 pages
Annotation
This paper describes a novel method for detecting trace amounts of human blood at crime scenes, based on immunofluorescence.
Abstract
This developed method is not only easy to use and human-specific, but is also reasonably fast in producing results in less than 45 minutes. The fixation technique developed enables an investigator to spray an area of interest. After drying, the fluorescent antibodies can be applied immediately, perhaps also in a spray form, without lengthy washing procedures. The use of two antibodies labeled with different distinct fluorophores allows not only the spatial locating of the blood stain, but also the location of the nucleated leukocytes. This will maximize the chances of recovering DNA, because it should be possible to pick out the leukocytes and take them forward for DNA profiling. Full DNA profiles with comparable peak area ratios to the controls were still achieved after this method was used. The ability of this method to detect older blood smears or droplets is of special importance for its usefulness in forensic science. Blood smears were left on slides for up to 4 months prior to analysis. Four monoclonal mouse anti-human antibodies were evaluated: Anti-glycophorin A for detecting erythrocytes and anti-CD45, anti-myeloperoxidase, and anti-histone to detect the nucleated leukocytes. Each antibody was labeled with either Alex Fluor 488 or 568 for direct application to blood smear, which allowed the simultaneous detection of erythrocytes and leukocytes. Because histones are DNA binding proteins, the application of anti-histone H1 allowed the detection of DNA within a blood smear. 3 tables, 5 figures, and 30 references