A sensitive radioassay for biotinidase activity: deficient activity in tissues of serum biotinidase-deficient individuals

Barry Wolf*, Julie Secor McVoy

*Corresponding author for this work

Research output: Contribution to journalArticle

31 Scopus citations


A new, sensitive radioassay for the determination of biotinidase activity was developed which measures the release of [14C-carboxylj-p-aminobenzoate fromN-biotinyl-[14C-carboxyl]-p-aminobenzoate. Biotinidase activity in serum from normal individuals is comparable to that determined by the colorimetric assay, but the radioassay is approximately 100 times more sensitive. Biotinidase deficiency was confirmed in the serum of patients who were previously shown to have reduced activities by the colorimetric assay. Although biotinidase activity was not detectable in extracts of normal peripheral blood leukocytes and fibroblasts using the colorimetric assay, activities could be measured by the radioassay. Using this method we demonstrated deficient biotinidase activity in extracts of leukocytes and fibroblasts from affected patients.

Original languageEnglish (US)
Pages (from-to)275-281
Number of pages7
JournalClinica Chimica Acta
Issue number3
Publication statusPublished - Dec 30 1983


ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Biochemistry, medical

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