The Detection Of Human Blood Essay

724 Words Mar 14th, 2016 3 Pages
1. Introduction Before the development of this immunoassay by Hurley et al. (2009) previous methods for the detection of human blood at crime scenes used ABAcard® and Hematrace®. Both tests, the enzyme-linked immunosorbent assay (ELISA) and the immunochromatographic test strips both use antigen-antibody interactions to confirm the presence of human blood. ABAcards® and Hematrace® strips utilise a monoclonal anti-human antibody which coats a test strip to test for haemoglobin whereas the ELISA utilises the most abundant antibody always present within the blood IgG by using anti-human IgG peroxidase this assay has a detection limit of 0.1µg/ml (Hurley et al., 2009). The detection limit of these strips is 0.07µg haemoglobin/ml (Johnston, Newman, & Frappier, 2003), therefore both tests show a similar detection limit but the immunochromatographic test strip tests for the presence of human haemoglobin but due to the highly sensitive nature false positive with other human bodily fluid such as saliva for example where trace amounts of haemoglobin can be present (Horjan, Barbaric, & Mrsic, 2016). The work done by Hurley et al. (2009) shown by the development of this immunoassay displays high specificity went tested against salvia, sweat, semen and tears without false positives. Both methods have benefits and limitation being the ELISA needs trained professionals and use of a lab an hour, but is highly specific (Hurley et al., 2009; Tokiwa, Tajima, Nishina, & Katsura, 1991).…

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