Prostate-Specific Antigen (PSA) with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Quantification
This test measures the level of prostate-specific antigen (PSA) in your blood using advanced mass spectrometry. PSA is a protein produced mainly by the prostate gland, often checked to monitor prostate health or screen for prostate cancer.
["PSA levels can help guide discussions about prostate health, but results alone don’t diagnose conditions."]
Key facts at a glance
- LOINC
- 2009-9
- Short code
- CA19-9
- Synonyms
- Cancer Ag19-9 SerPl Ql
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or red-top tube; plasma may be collected in lithium heparin or EDTA tubes
- Units
- N/A
- Ref low
- 0
- Ref high
- 37
- Critical range
- 0.5 N/A – —
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (Chemiluminescent Immunoassay [CLIA] or Electrochemiluminescence Immunoassay [ECLIA])
- CPT
- 86301
- SNOMED
- 1152680004
- Specimen volume
- 1-2 mL of serum or plasma (minimum 0.5 mL)
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 3 months. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 100
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like urinary issues, pain in the pelvic area, or if you’re at higher risk for prostate problems. It can also be used during routine check-ups, especially for men over 50, those with a family history of prostate cancer, or those with an enlarged prostate.
What to Expect Before the Test
No special preparation is needed, but you may be asked to avoid ejaculation for 2–3 days before testing to get the most accurate results. Drink plenty of water the day of your visit to help your blood flow smoothly.
What Happens During the Test
A healthcare professional will draw blood from a vein in your arm. The sample is then sent to a lab for analysis using mass spectrometry, which detects PSA with high precision.
What the Results Mean
PSA levels vary widely among individuals. While higher levels may raise concerns about prostate issues, they don’t always indicate cancer. Your results will be discussed with your provider in the context of your overall health and symptoms.
Reference range
Normal: <37 U/mL (commonly cited upper reference limit). Values may vary by laboratory and assay manufacturer.N/A
No special patient preparation required. Fasting is not necessary. However, sample should be drawn before any procedures that may cause transient elevation. Follow standard venipuncture procedures.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
PSA Blood Test (LC-MS/MS)
Frequently asked questions
What does a PSA test measure?
How often should I get a PSA test?
Can PSA levels be affected by diet or medications?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy