PSA

Test Code

PSA

Alias/See Also

Prostatic specific antigen
PSA,PLASMA
Chemistry

Preferred Specimen

Gold Top Tube

Minimum Volume

2 mL

Transport Temperature

Refrigerated (2-8°C): 24 hours.
Separate if not tested within this time and freeze at -20°C or colder.

Specimen Stability

Refrigerated (2-8°C): 24 hours.
Separate if not tested within this time and freeze at -20°C or colder.

Methodology
This assay is a two-step immunoassay for the quantitative determination of total PSA (both free PSA and PSA complexed to alpha-1-antichymotrypsin) in human serum using chemiluminescent microparticle immunoassay (CMIA) technology.
Patient results determined by assays using different manufacturers or methods may not be comparable.

Setup Schedule

M-F

Report Available

TAT 1 - 3 days

Limitations

Specimens from patients who have received preparation of mouse monoclonal antibodies for diagnosis or therapy may contain human anti-mouse antibodies (HAMA). Such specimens may show either falsely elevated or depressed values when tested with assay kits which employ mouse monoclonal antibodies.28, 29 Alinity i Total PSA reagents contain a component that reduces the effect of HAMA reactive specimens. Additional clinical or diagnostic information may be required to determine patient status.
Heterophilic antibodies in human serum can react with reagent immunoglobulins, interfering with in vitro immunoassays. Patients routinely exposed to animals or to animal serum products can be prone to this interference, and anomalous values may be observed. Additional information may be required for diagnosis.30
The concentration of PSA in a given specimen, determined with assays from different manufacturers, can vary due to differences in assay methods, calibration, and reagent specificity.1, 31, 32

Quality control samples may be produced by introducing seminal fluid PSA into a human serum matrix. PSA in serum and seminal fluid may exist in different forms. The concentration of PSA in these controls, determined with assays from different manufacturers, can vary due to differences in assay methods, calibration, reagent specificity, and the form of PSA that is present; therefore, it is important to use assay-specific values to evaluate control results.
Hormonal therapy may affect PSA expression; therefore, a low PSA level after any treatment that includes hormonal therapy may not adequately reflect the presence of residual or recurrent disease.33
In most instances, specimens obtained from patients immediately following digital rectal examination show no clinically significant increases in PSA levels.34 However, prostatic massage, ultrasonography, and needle biopsy may cause clinically significant elevations.35 PSA levels may also be increased following ejaculation.36
Active free PSA in the serum at the time of blood sampling can continue to complex with serum protease inhibitors, especially alpha-2-macroglobulin, resulting in a rapid decrease in PSA levels of the active form of free PSA.37
Serum PSA concentrations should not be interpreted as absolute evidence for the presence or absence of prostate cancer. Elevated concentrations of PSA may be observed in the serum of patients with benign prostatic hyperplasia or other nonmalignant disorders as well as in prostate cancer. Furthermore, low PSA concentrations are not always indicative of the absence of cancer. The PSA value should be used in conjunction with information available from clinical evaluation and other diagnostic procedures such as DRE. Some early cases of prostate cancer will not be detected by PSA testing; the same is true for DRE. Prostatic biopsy is required for the diagnosis of cancer.

Reference Range

0 - 4.0 ng/mL

Clinical Significance

Elevated serum PSA concentrations have been reported in men with prostate cancer, benign prostatic hypertrophy, and inflammatory conditions of the prostate.

Performing Laboratory
Test performed in these BACL Chemistry Labs
Contact: Jonathan Dryjowicz-Burek, West Roxbury 857-203-5973
Alternate contact Diane Robert BR 774-826-2294
Alternate contact Bhumikaben Patel Bedford 781-687-2976

Last Updated: December 19, 2025

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.