Besides the water-soluble elastin conjugate (Cat # AS-85113), this water-insoluble fluorescent conjugate can be used for fluorometric measurement of elastase activity. This product is insoluble bovine neck ligament elastin that is heavily labeled with FITC such that the conjugate's fluorescence is quenched. Upon digestion by elastase or other proteases, the fluorescence is recovered. Digestion products from the elastin substrate have absorption maxima at ~490 nm and fluorescence emission maxima at ~520 nm. This insoluble elastin derivative is more specific for elastase than AS-85113.