Vitamin B-12

For Laboratory Research Use Only — Not for Human or Veterinary Use.

Standard (< 1,000 vials)$140/kit

Volume (1,000+ vials)$100/kit

Quantity (kits)

= 10 vials

Minimum order: 100 vials total. Mix and match across all products.

I confirm this order is for laboratory research use only.For Laboratory Research Use Only — Not for Human or Veterinary Use. By checking this box you affirm this product will not be used for human or animal administration.

Specifications

CAS Number	68-19-9
Molecular Formula	C63H88CoN14O14P
Molecular Weight	1355.37 g/mol
Purity	≥98% (HPLC)
Form	Lyophilized Powder
Storage	-20°C, desiccated, protected from light
Reconstitution	Bacteriostatic water

Certificate of Analysis

Lot documentation

Every production lot is independently third-party tested. A batch-specific Certificate of Analysis — documenting HPLC purity, mass spectrometry identity confirmation, and net peptide content — is issued with every shipment. View a sample COA to see the format.

View Sample COA About our testing →

Research context

A cobalt-containing corrinoid, not a peptide. Supplied as a crystalline solid with light protection as the governing handling requirement.

Structure and chemical class

Vitamin B-12 is not a peptide, and treating it as one leads to the wrong handling and the wrong analysis. It is a cobalamin: a cobalt ion held at the centre of a corrin macrocycle, a structure resembling a porphyrin but with one fewer bridging carbon. It is among the largest and most structurally complex small molecules in routine laboratory use.

The compound is supplied as cyanocobalamin, in which a cyanide group occupies the upper axial coordination site on the cobalt. That form is the most stable and the most common commercially. Hydroxocobalamin and the biologically active methylcobalamin and adenosylcobalamin differ only in the ligand at that single position, and they interconvert readily, which is the fact that governs its handling.

Findings in the published research literature

The biochemistry is long established. Cobalamin is a cofactor for two enzyme classes: methionine synthase, where methylcobalamin transfers a methyl group in the folate cycle, and methylmalonyl-CoA mutase, where adenosylcobalamin supports a radical rearrangement. Cobalamin-dependent radical chemistry remains an active area of mechanistic enzymology because the carbon-cobalt bond is one of very few organometallic bonds in biology.

In a laboratory context the compound also serves as a spectroscopic and analytical standard, since its visible absorbance spectrum is distinctive and well characterised. Its presence in this category reflects catalogue convention rather than shared mechanism: it is a cofactor, not an immune signalling peptide.

Analytical verification

Verification here is small-molecule analysis rather than peptide analysis. Ultraviolet-visible spectrophotometry is the primary and most convenient identity check, since cyanocobalamin has a characteristic three-band spectrum, and the ratio between those bands reports on the axial ligand and therefore distinguishes cyanocobalamin from hydroxocobalamin directly.

HPLC with diode-array detection establishes purity, and a Certificate of Analysis for this material should read as a small-molecule specification, with water content and residual solvent rather than deletion sequences and disulfide status. The characteristic deep red colour is itself a useful first-pass check: material that has faded or shifted toward orange has degraded.

Handling and storage

Solubility	Freely soluble in water, giving a deep red solution. No co-solvent required.
Reconstitution	Dissolves readily. Prepare in amber glassware or wrap the vessel in foil.
Storage	Solid at 2-8C, protected from light. Light protection is the governing requirement for this compound and is not optional.
Stability	Photolysis is the dominant degradation route: light cleaves the cobalt-cyanide bond and converts cyanocobalamin to hydroxocobalamin. This proceeds under ordinary laboratory illumination on a timescale of hours for dilute solutions, so a solution left uncovered on a bench is a different compound by the end of the day.