Vitamin B12
Label Mnemonic: B12
Epic Lab Code: LAB67
Downtime Form: A-1a General Laboratory Requisition
Chemistry
6240 RCP
356-3527
Specimen(s):
Plasma
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
Minimum:
3 mL whole blood in light green top tube or TWO Microtainer® devices.
Delivery Instructions:
Deliver to laboratory immediately after collection.
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
Normal: 232 - 1245 pg/mL
Indeterminate: 150 - 231 pg/mL
Deficient: is less than 150 pg/mL
Comments:
This assay may be significantly impacted by high-dose biotin (>5 mg dose) taken within previous 12 hours. High concentrations of biotin may lead to falsely decreased results. These concentrations may be found in patients taking over-the-counter supplements with biotin content much higher than nutritional requirements for biotin. Specimens should not be collected until at least 12 hours after the last dose.

Refer to BD Microtainer® Tubes product sheet for detailed sample collection instructions.

New analytical immunoassay with different reference range instituted on 12/19/2017.

This test is also performed in the Iowa River Landing (IRL) clinical laboratory (for specimens drawn at that site).
Test Limitations:
The assay is unaffected by icterus (bilirubin is less than 65 mg/dL), hemolysis (Hb is less than 1.0 g/dL), lipemia (triglycerides is less than 1500 mg/dL) and biotin is less than 50 ng/mL. (criterion: recovery within plus or minus 10% of initial value).

No interference was observed from rheumatoid factors up to a concentration of 1500 IU/mL.

In vitro tests were performed on 16 commonly used pharmaceuticals. No interference with the assay was found.

In rare cases interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.

This assay is designed to avoid interference due to anti-intrinsic factor antibodies.
For diagnostic purposes, the vitamin B12 findings should always be assessed in conjunction with the patient's medical history, clinical examination and other findings.
Methodology:
Electrochemiluminescence Immunoassay
CPT Code:
82607