Carbohydrate Antigen (CA) 19-9 (Serial Monitor)

The account must submit the patient's Social Security number to monitor. Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient's course of therapy. To order this test without the serial monitor service, use test 002261. For a complete test description, see Carbohydrate Antigen (CA) 19-9.

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.