Acid Phosphatase 

Updated: Mar 19, 2014
  • Author: Anas K Gremida, MD; Chief Editor: Thomas M Wheeler, MD  more...
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Reference Range

The reference value for acid phosphatase is 2 ng/mL or less.



Conditions associated with elevations in prostatic acid phosphatase (PAP) include the following:

  • Benign prostatic hyperplasia

  • Prostatic infarction

  • Manipulation of the prostate through a massage or rectal examination


Collection and Panels

Specifics for collection and panels are as follows:

  • Specimen type: Blood serum

  • Container: Vacutainer, red/black top (preferred) or red top (see image below)

    empty para to satisfy content model empty para to satisfy content model
  • Collection method: Venipuncture

  • Specimen volume: 1 mL

  • Other instructions:

Related tests: Prostate-specific antigen (PSA)




Acid phosphatases are enzymes that are capable of hydrolyzing phosphate esters in an acidic environment. Prostatic acid phosphatase (PAP), which is produced in the prostate, was the first major serum marker for prostate cancer, and was used widely for screening, staging, and post-treatment monitoring. Its use has largely been displaced by PSA. [1, 2, 3]


Indications for testing of PAP include the following:

  • Additional prognostic information for predicting recurrence after radical prostatectomy for clinically localized prostate cancer

  • Additional monitoring of therapeutic response in prostate cancer treated by androgen ablation

  • Can also be used medicolegally as presumptive test to indicate the presence of semen in cases of sexual abuse