title: Determination of biocytin.
abstract: Biocytin (epsilon-N-[d-biotinyl]-L-lysine) is generally undetected in serum and other body fluids of normal healthy individuals in view of the ubiquitous distribution of biotinidase. It has been suggested that biocytin may be present in serum and urine of patients with inherited biotinidase deficiency. We have developed a noncompetitive assay for biocytin based on its interaction with avidin. Biocytin can be determined in biological samples containing both biotin and biocytin. Biotin from such samples is removed by an anion-exchange resin and the biocytin is determined by the avidin-binding assay. The effect of above-normal levels of biotin in the sample on the assay of biocytin is discussed.
mesh_terms: D000328:Adult; D000837:Anion Exchange Resins; D001360:Avidin; D001665:Binding Sites; D001667:Binding, Competitive; D001710:Biotin; D006801:Humans; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood / Q000652:urine
chemical_list: D000837:Anion Exchange Resins; D001360:Avidin; D001710:Biotin; C013411:biocytin; D008239:Lysine