Vitamin B12, Reflexive

Label Mnemonic:	B12R
Epic code:	LAB882
Order form:	Laboratory Requisition
Supply order:	Supply Order Form
Billing:	Billing Policies
CPT code:	82607

Specimen(s):

Serum

Collection Medium:

Red top tube 5 mL (Clot Activator)

Alternate Collection Media:

Call laboratory for additional acceptable specimen collection containers.

Minimum:

3 mL whole blood in red top tube or THREE Microtainer^® devices.

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

New analytical immunoassay for vitamin B12 with different reference range instituted on 12/19/2017.

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 increased 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.

This test reflexes to methylmalonic acid if vitamin B12 < 300 pg/mL and additionally to intrinsic factor blocking antibody if vitamin B12 < 211 pg/mL. These reflex tests carry additional charges if performed.

Please print, complete and submit the Advance Beneficiary Notice (ABN) along with the Laboratory Requisition before shipping the specimen.

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 U/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

Instructions:

Centrifuge, remove serum or plasma, aliquot to plastic tube labeled with patient's name and date drawn. Refrigerate and protect from light.

Sample Processing:

Centrifuge within two hours of draw time.
Centrifuge at 3000 RPM for 10 minutes.
Transfer serum/plasma into a new screw-capped plastic vial.

Sample Storage:

Refrigerate.

Transport Instructions:

Place requisition into outside pocket of bag.
Place specimen into zip-lock type bag, seal bag.
Place dry ice on top of specimen in Styrofoam container.
Dry Ice up to 24 hours.

CPT Code:

82607

See Additional Information:
Biotin Interference with Immunoassays