The shelf life is related to many factors, storage state, buffer ingredients, storage temperature and the stability of the protein itself. Generally, the shelf life of liquid form is 6 months at -20°C/-80°C. The shelf life of lyophilized form is 12 months at -20°C/-80°C.
Repeated freezing and thawing is not recommended. Store working aliquots at 4°C for up to one week.
A constitutively expressed secondary porin, forms a water-filled channel which favors the permeation of cations and less efficiently phosphate. There are about 2400 porins in wild-type, 800 in an mspA deletion and 150 in a double mspA-mspC deletion.