The rate of lysis of Micrococcus lysodeikticus is determined as suggested by
Shugar (1952). One unit is equal to a decrease in turbidity of 0.001 per minute at 450
nm at pH 7.0 and 25°C under the specified conditions. A wide range of activities are
reported for pure lysozyme preparations under these conditions. The Worthington specific
activity of 8,000 u/mg dw is equivalent to 50,000 u/mg dw claimed by other suppliers.