Comparative Study of Four Methods of Determining Alkaline Phosphatase

MEASUREMENT of activity of serum alkaline phosphatase has provided the clinician with valuable aid in confirming his diagnosis of disease of the hepatobiliary and skeletal systems. After the demonstration of a serum alkaline phosphatase in 19241 , 2 several analytical methods for clinical laboratory use were proposed, including those of Bodansky,3 King–Armstrong4 and Bessey–Lowry–Brock.5 Recently, another modification, employing phenolphthalein diphosphate as a substrate, has been proposed as a rapid and sensitive method of determining serum alkaline phosphatase activity.6 The primary difference among the tests resides in the different substrates employed, although they also differ in substrate concentration, temperature, pH, buffer and incubation . . .