Effect of storage in deep freeze upon activity of urinary acid phosphatase.

Abstract

It has been reported that the acid phosphatase of serum is inactivated after several days at room temperature, or even in a refrigerator, but the activity may be preserved for periods ranging up to 112 days at —15 C. Similar findings were reported for the acid phosphatase of leukocytes. We also found that temperatures maintained in a deep-freeze prevent inactivation of the acid phosphatase in tissue extracts and fluid. However, while studying total and prostatic acid phosphatase in serum,' we observed that urine which was placed in a deep-freeze for 24 hours or longer seemed to lose considerable activity of acid phosphatase. Inasmuch as the excretion of urinary acid phosphatase has been studied in certain physiologic and pathologic states, the problem of proper preservation of urine is important. Therefore, we decided to study the extent of inactivation of urinary acid phosphatase under freezing conditions, and to attempt to define the mechanism through which the inactrvation occurred.