The acid phosphatase test measures the level of acid phosphatase in the blood. Acid phosphatase is an enzyme found in the prostate gland, semen, liver, spleen, blood cells, and bone marrow. If these organs and tissues are not functioning right, they may release acid phosphatase into the bloodstream.

Who is a candidate for the test?

The acid phosphatase test is used primarily to diagnose and stage cancer of the prostate and to monitor the effect of the treatment. It may also be used to detect damage to the heart, liver, and other organs.

How is the test performed?

To measure the amount of acid phosphatase in the blood, a blood sample is taken from a vein in the arm. First, the skin over the vein is cleaned with an antiseptic. A tourniquet is wrapped around the upper arm to enlarge the veins. A small needle is inserted into a vein, and blood is collected for testing in the laboratory. After the tourniquet is removed, a cotton ball is held over the needle site until bleeding stops.