Separation of Bound and Free Vit. B 12 on Sephadex G-25 Column. ∗

Summary and conclusions

A good separation of bound from free Vit. B₁₂ is obtained on Sephadex G-25 columns in mixtures containing free Vit. B₁₂ and Vit. B₁₂ bound to binders of the normal human gastric juice. Sephadex G-25 fractionation method may be very useful in the assay of Vit. B₁₂ binding capacity of biological Vit. B₁₂ binders and intrinsic factor materials from human and animal sources.