3.4.22.24	-70°C, in 50 mM sodium phosphate buffer, pH 6.5, 25 mM NaCl, 12.5% glycerol, 1 mM DTT, at least 2 months	
3.4.22.24	4°C, at somewhat higher ionic strength than 50 mM sodium phosphate, pH 6.5, 25 mM NaCl, 12.5% glycerol, 1 mM DTT, inactivation within 1 week