1 - 3 days
Free PSA Ratio
PSA Total and Free, S
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Electrochemiluminescent Immunoassay (ECLIA)
The percentage of measured PSA existing in the free form (free:total PSA ratio) is useful in assessing the risk of prostate cancer in patients with borderline or moderately increased total PSA (4-10 ng/mL).
When total PSA is in the range of 4.0-10.0 ng/mL, a free:total PSA ratio < or =0.10 indicates 49% to 65% risk of prostate cancer depending on age; a free:total PSA ratio >0.25 indicates a 9% to 16% risk of prostate cancer, depending on age.
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Collect specimen in an SST or red top tube. Refrigerate and send intact specimen within 3 hours of collection. Alternatively, centrifuge, aliquot serum into a plastic vial within 3 hours of collection and freeze.
Collect specimen in an SST or red top tube. Centrifuge, aliquot serum into plastic vial within 3 hours of collection and freeze. Transport to MLabs as a frozen aliquot.