CSI teams beware — an increasingly common household product cleans up blood thoroughly enough to make it undetectable by three of the most common forensic tests, scientists are reporting in an upcoming Naturwissenschaften.
![Household “oxy” cleaners remove blood almost too well, which could prevent forensic investigators from finding the clues that usually show up in routine tests, such as the luminol test above](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2008/11/9402.jpg?resize=300%2C300&ssl=1)
These “presumptive tests” are a quick and dirty means of identifying important stains — such as blood — at a crime scene. “They tell you what to collect,” says Walter Rowe, chair of the forensic sciences department at George Washington University, who was not involved with this study. The tests rely on the blood protein hemoglobin’s love of oxygen.
But the various “oxy” cleaners that have arrived on the scene in recent years appear to drown the hemoglobin in so much oxygen that the protein’s got no love left for the tests.