Household Cleaners Using Oxygen May Make Blood Removal Too Simple: Three Common Forensic Tests Foiled by Hemoglobin's Fatigue
Ehrenberg, Rachel, Science News
CSI teams beware -- a common household product cleans up blood thoroughly enough to make it undetectable by three of the most common forensic tests.
These "presumptive tests" are a quick-and-dirty way to identify important stains--such as blood--at a crime scene, says Walter Rowe of George Washington University in Washington, D.C. The tests rely on the blood protein hemoglobin's love of oxygen. But "oxy" cleaners appear to drown hemoglobin in so much oxygen that the protein has no love left for the tests, scientists report in an upcoming Naturwissenschaften.
While the research suggests a way for immaculate killers to clean the scene, most people who commit murder aren't in a frame of mind to think over which detergent to use to cover their tracks, Rowe points out. "People committing violent crimes often don't have time to clean up; they leave a lot of stuff behind."
Hemoglobin, a doughnut-shaped protein made of four globular subunits, carries oxygen from the lungs to the body's tissues. Each subunit has its own heme group, a bit of iron bound in a protein ring. It's the iron that's mad about oxygen. Existing forensic blood tests involve swabbing the stain with hydrogen peroxide. …