Solid-phase vitamin B12 assays using polyacrylamide-bound intrinsic factor and polyacrylamide-bound R-binder.

A new solid phase vitamin B12 assay is described using intrinsic factor to measure microbiologically-available B12 and R-binder to measure total B12. The solid phase reagent consists of intrinsic factor coupled to polyacrylamide beads and salivary R-binder coupled to polyacrylamide beads. The assay is simple to perform and separates completely sera from controls and patients with megaloblastic anaemia due to B12 deficiency.