A comparison of vitamin B₁₂ levels in the livers and sera of sheep measured by microbiological and radioassay methods

Abstract

Five radioassay methods (commercial kits) were evaluated for the determination of vitamin B₁₂ in sheep serum. They provided results that correlated significantly (P<0.01) with those obtained using a microbiological assay.

One radioassay method was evaluated for analysing vitamin B₁₂ in liver, and the results were in excellent agreement with those obtained by the microbiological method.

Little correlation between serum and liver vitamin B₁₂ levels was found. The limited diagnostic value of serum vitamin B₁₂ concentrations for detecting cobalt deficiency in sheep is discussed.