Active B12, Serum

Diagnostic Use

Active B12 (holotranscobalamin) is used as an aid in the diagnosis and monitoring of treatment for vitamin B12 deficiency.

Department

Endocrinology Lab

Delphic Registration Code

AB12

Synonyms

HoloCT
Holotranscobalamin

Turnaround Time

7 days

Test Code

5482

Specimen Type

• Serum

Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Preferred if West Coast

• SST II (Gold Cap)

Acceptable

• SST II (Gold Cap)

Preferred Sample Volume (ml)

5

Minimum Sample Volume (ml)

1

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Serum (Red Cap)

Acceptable

• SST II (Gold Cap)

Preferred Sample Volume (ml)

0.5

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

Lithium heparin and EDTA blood collection tubes are unacceptable sample types.

Aliquot Instructions

Sample Type

• Serum

Minimum Volume (ml)

0.5

Transport to Lab

Chilled (2 - 8 degrees Celsius)
If overnight - Chilled (2 - 8 degrees Celsius)

Additional Referral/Aliquot Information

Stable 7 days 2-8, if separated from cells.

Interpretation

	Comment
<37 pmol/L	Vitamin B12 deficiency is likely.
≥37 – <58 pmol/L	Holotranscobalamin is in the equivocal range. The result should be interpreted  in the context of signs, symptoms, and risk factors for vitamin B12  deficiency. Further measurement of functional markers of vitamin B12 status,  such as serum methylmalonic acid and/or total homocysteine, may be of value.
≥ 58 pmol/L	Vitamin B12 deficiency is unlikely.

Reference Intervals

2.5^th -97.5^th percentile reference interval:     37.5-150 pmol/L

Manufacturers data

Test Method

Roche Electrochemiluminescence immunoassay

Non-Funded Test Cost

$30.46 (Exclusive of GST)

Billing Code

5482

Contact Information

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