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HelpTest Code 0212902 Prostate Specific Antigen (PSA), Total and Free, Serum
Methodology
Chemiluminescent microparticle immunoassay (CMIA)
Performing Laboratory
Alomere Health Hospital Laboratory
Specimen Requirements
Specimen Type: Serum only
Collection Container/Tube: Gold (gel separator) or Red (plain)
Specimen Volume: 2.0 mL
Specimen Minimum Volume: 0.2 mL
Collection Instructions:
1. Allow serum tubes to clot completely. This may take up to 30 minutes.
2. Remove sample from cells by pipetting.
Reject Due To:
Plasma submitted
Specimen Transport Temperature
For Free PSA - Centrifuge and separate off cells within 3 hours
Within 48 hours: Refrigerated (when centrifuged and separated off cells)
>48 hours: Frozen
Reference Values
The % free PSA (Free/Total Ratio) is, on average, lower in prostate cancer (PCa) than in BPH and has been commonly used as an aide in PCa diagnosis when the total PSA value is in the “gray zone” (between 4-10 ng/mL). Our reference laboratory, Mayo Medical Laboratories, uses the following criteria:
| If the Total PSA is between 0.00-4.00 ng/mL | |
| Total Ratio | Cancer Rate |
| <10% | >40% |
| >25% | <10% |
This testing method is a Chemiluminescent Immunometric assay using the Abbott i1000.
Values obtained with different assay methods or kits may be different and cannot be used interchangeably. Test results cannot be interpreted as absolute evidence for the presence or absence of malignant disease.
Day(s) Test Set Up
Monday through Friday
Test Classification and CPT Coding
84153 - PSA. Total
84154 - PSA, Free