KPL TrueBlue is up to 100 times more sensitive than DAB and it is free of known carcinogens. Strong blue reaction product provides excellent contrast with DAB and other substrates. KPL TrueBlue provides the most sensitive means available to detect peroxidase-labeled conjugates. Because of its high sensitivity, TrueBlue is recommended for detection of the least abundant marker. KPL TrueBlue is alcohol and xylene insoluble.