Improved determination of prostatic acid phosphatase (sodium thymolphthalein monophosphate substrate)

We have modified a previously described method for determining acid phosphatase, with thymolphthalein monophosphate as substrate, to increase its sensitivity. We assessed effects of serum on variables influencing acid phosphatase activity as measured by this method. The method is shown to be not completely specific for prostatic acid phosphatase. The importance of standardizing methodology in measurement of enzyme activities is demonstrated.