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Test Code CA199 Carbohydrate Antigen 19-9 (CA 19-9), Serum

Reporting Name

Carbohydrate Ag 19-9, S

Useful For

As a potential adjunct for diagnosis and monitoring of pancreatic cancer


Potentially differentiating patients with cholangiocarcinoma and primary sclerosing cholangitis (PSC) from those with PSC alone

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type


Specimen Required

Patient Preparation: For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.


Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.6 mL

Collection Instructions:

1. Serum gel tubes should be centrifuged within 2 hours of collection.

2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection 

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
  Frozen  90 days
  Ambient  8 hours

Reference Values

<35 U/mL 

Day(s) and Time(s) Performed

Monday through Friday; 5 a.m.-12 a.m.

Saturday; 6 a.m.-6 p.m.

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CA19 Carbohydrate Ag 19-9, S 83084-4


Result ID Test Result Name Result LOINC Value
CA19 Carbohydrate Ag 19-9, S 83084-4

Clinical Reference

1. Torok N, Gores GJ: Cholangiocarcinoma. Semin Gastrointest Dis. 2001 Apr;12(2):125-132

2. Scara S, Bottoni P, Scatena R: CA 19-9: Biochemical and clinical aspects. Adv Exp Med Biol. 2015;867:247-60. doi: 10.1007/978-94-017-7215-0_15

Method Description

The Access GI Monitor assay is a 2-site immunoenzymatic sandwich assay. A sample is added to a reaction vessel along with paramagnetic particles coated with polyclonal goat-antibiotin antibody, mouse monoclonal-biotin conjugate, and a buffered protein solution. After incubation in a reaction vessel, separation in a magnetic field and washing remove materials not bound to the solid phase. A monoclonal-alkaline phosphatase conjugate is then added. After incubation in a reaction vessel, materials bound to the solid phase are held in a magnetic field, while unbound materials are washed away. The chemiluminescent substrate is added to the vessel and light generated by the reaction is measured with a luminometer. The light production is directly proportional to the concentration of carbohydrate antigen 19-9 in the sample. The amount of analyte in the sample is determined from a stored, multipoint calibration curve.(Package insert: Access GI Monitor. Beckman Coulter; 04/2020)

Analytic Time

Same day/1 day

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross Icterus OK

Method Name

Immunoenzymatic Assay


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Oncology Test Request (T729)