Also called: acid phos, acid f, acid p’tase. A test of blood serum to detect a specific enzyme produced by several tissues, particularly the prostate. Acid phosphatase levels are elevated in 85% of cases with skeletal metastases, 60% of untreated cases, and 20% of localized cases. Usually ordered as a separate laboratory test. May also be ordered as prostatic acid phosphatase (PAP), a measure of acid phosphatase secreted by prostate gland cells specifically. Note: test results may be affected by recent prostatic massage or palpation; acid phosphatase level should be assayed before digital rectal examination. Normal range: varies according to method of processing the serum: 1.0 — 4 King Armstrong microns/dl 0.5 — 2 Bodansky or Gutman microns/dl 0 — 1.1 Shinowara microns/ml 0.1 — 0.73 Bessy Lowry microns/nk. 0.5 — 11.0 unit/L