Stability of isoenzymes of alkaline phosphatase in various buffer systems.

The stability of isoenzymes of alkaline phosphatase from liver, bones and small intestine was compared after addition to inactivated serum in the buffer systems: glycine, 2-amino-2-methyl-1-propanol, diethanolamine and 2-amino-2-methyl-1,3-propandiol at 37 degrees C. The mentioned isoenzymes were inactivated to different extents in glycine and 2-amino-2-methyl-1-propanol buffers. In diethanolamine and 2-amino-2-methyl-1,3-propandiol buffers sufficient stability of isoenzymes is obtained so that only these buffers are suitable for activity determinations of alkaline phosphatase at 37 degrees C.