1.7.7.1 repetitive freezing and thawing or prolonged dialysis produces a loss of enzyme activity 394396 1.7.7.1 the stability of the enzyme depends on the salt concentration. The maximum stability is found in the presence of 3.6 M NaCl 727542 1.7.7.1 unstable in crude extracts and in solutions below pH 7 394413 1.7.7.1 when the enzyme is dialysed against a 50 mM phosphate buffer, pH 7.0, containing 20% glycerol, the enzyme can be stored for 2 weeks without any significant loss of activity 727542