Neuraminidase (sialidase) removes N-acetyl neuraminic acid (sialic acid) from a variety of glycoproteins. The enzyme has an optimum pH of 5.0-5.1. Little or no activity is observed at pH 4.0 or above pH 8.0. Chromatographically purified. A lyophilized powder containing 50% (w/w) sucrose. Contaminating proteolytic activity 0.1% using trypsin as the standard.