Amido black is an effective blood reagent when latent or difficult to see blood stains are present. AB will develop exceptional fine detail as needed in bloody fingerprints and footwear impressions. Amido black reacts with blood proteins to create a deep blue color change. The water based formulation includes a blood fixative in the ready to use application, perfect for crime scene processing. For crime scene use apply directly to suspected stains. Nonporous surfaces tend to yield the best results with Amido black and require little or no over stain rinsing. An application using a wash bottle (sold separately) is preferred for the completeness of coverage over spray methods.