PAA/AMG can be prepared in 50 mM sodium maleate buffer containing BSA for use in the assay. When prepared in buffer it needs to be used within 4 hours of preparation.
Alternatively, it is possible to prepare as an ammonium sulphate suspension, which allows for the storage of this prepared enzyme. Once prepared as an ammonium sulphate suspension it can be stored for up to 3 months at 4˚C or aliquoted and stored below -10˚C for > 3 years.
When using the ammonium sulphate suspension preparation in the method there is an extra buffer addition required which is not required when using the buffer enzyme preparation, hence some users prefer the use of the buffer preparation.
The ammonium sulphate suspension preparation is recommended for any users that may have sensitivity to using the PAA/AMG enzyme.