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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: CA 19-9 (Cancer Antigen-GI)

Test Code(s): CA199 / XCA199

CPT Code(s): 86301

Methodology: Chemiluminescent Immunoassay

Days Performed: Daily, 24 hours.

Turnaround Time: Stat: 1 hour.
Routine: 4 hours.

Specimen Requirements

Specimen: Blood

Collection Container: Preferred: Green cap with yellow ring (PST)
Also Acceptable: Green top, Red cap with yellow ring (SST), Red top

Collection Volume: Preferred: 1 mL
Pediatrics: 0.5 mL

Sample Analyzed: Plasma or serum

Volume Required: Preferred: 0.5 mL
Pediatrics: 0.15 mL

Specimen Processing: Centrifuge blood within 2 hours of collection.  If a complete barrier has not formed, transfer cell-free plasma/serum to plastic vial.  Refrigerate.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport with coolant pack if coming from outreach location.

Stability: Ambient: 2 hours on cells; 8 hours off cells
Refrigerated: 7 days at 2-8 C
Frozen: 12 months at or below -20 C


Reference Interval:

0 days and up:  Up to 37 Units/mL

Test Limitations:

This method is indicated for the serial measurement of CA19-9 to aid in the management of patients diagnosed with cancers of the exocrine pancreas.  The Siemens Dimension Vista LOCI CA19-9 assay is not intended for screening or diagnosis of pancreatic cancer.


Patients must possess the ability to express the Lewis blood group antigen or they will be unable to produce the CA19-9 antigen even in the presence or proven malignancy.


Results may be affected if patient has developed heterophillic antibodies due to exposure to animal based protein products.


A high dose hook effect is not seen up to 1,000,000 U/mL.

Additional Information:

The Siemens Dimension Vista LOCI CA19-9 method is used.  Results obtained with different assay methods or kits cannot be used interchangeably.

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