title: Radioisotopic assay of serum vitamin B 12 .
mesh_terms: D000328:Adult; D000368:Aged; D003036:Cobalt Isotopes; D005260:Female; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D011485:Protein Binding; D011865:Radioisotope Dilution Technique; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D003036:Cobalt Isotopes; D014805:Vitamin B 12