The leuco malachite green reaction is based on the reduction of malachite green, when heated in acid solution, to colorless leuco malachite green. This reaction is then reoxidized when it comes into contact with blood to produce a green end point. The method uses nylon membranes as the lifting media which have previously been impregnated with leuco malachite green. Membranes are activated with deionized water and placed on marks, producing excellent lift and enhancement simultaneously from a variety of different substrates. The method should prove extremely useful at crime scenes to obtain marks on immovable subtrates that are difficult to photograph in situ and should also be useful in areas where the application of chemicals may pose health and safety problems. 1 reference and 3 tables