Name: Vitamin B12
Test Name: Vitamin B12
Health Link Test Code: B12
LIS Test Code: B12
CPT Code(s): 82607
Methodology: Chemiluminescent Immunoassay
Days Performed: Daily.
In-Lab Turnaround Time: 4 hours.
Stat In-Lab Turnaround Time: Not available stat.
Collection Container: Red cap with yellow ring (SST)
Also Acceptable: Red top
Collection Volume: 1 mL
Pediatric Collection Volume: 0.5 mL
Sample Analyzed: Serum
Testing Volume: 0.5 mL
Pediatric Testing Volume: 0.2 mL
Centrifuge blood within 2 hours. Transfer cell-free serum to plastic vial. Refrigerate. If transport time exceeds 48 hours, freeze serum sample.
Transport specimen to Laboratory. Transport with coolant pack if coming from clinic location. Transport frozen specimen on dry ice.
Hemolyzed specimens are not acceptable.
18 years and up: 213-816 pg/mL
Interpretation Type: Reference Interval
Intrinsic Factor blocking antibodies are present in approximately half of pernicious anemia patients. There is a low frequency possibilty that these antibodies may not be completely inactivated during the reaction pretreatment step. If test results are in conflict with the clinical diagnosis, consider testing for intrinsic factor blocking antibodies.
Patient samples may contain heterophilic antibodies that could react in immunoassays to give falsely elevated or depressed results. A test result that is inconsistent with the clinical picture and patient history should be interpreted with caution.
Special Instructions: Effective 7/3/17, the acceptable tube type for Vitamin B12 Testing is SST or Red Top tube. This is due to an artifact identified in the green top tubes that caused occasional spuriously high results.