Hemastix are most commonly used as a dip and read test for blood in urine. Hemastix can be used at crime scenes to determine if what is being photographed at the scene is actually blood spatter. It is a quick and easy test which detects the peroxide-like activity of hemoglobin in a substance. Simply rub the Hemastix on a moistened stain or across a swab that has a suspected dried blood sample on it. The reagent coated tip will turn a shade of green if hemoglobin is detected. If the reaction is positive, take a photograph of the strip by the substance to document the reaction and retain the strip as evidence. Contains 50 strips.