A sensitive fluorometric assay for avidin and biotin

✍ Scribed by Henry J. Lin; Jack F. Kirsch

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 252 KB
• Volume: 81
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(77)90715-1

✦ Synopsis

The quenching of the tryptophan fluorescence of avidin by biotin forms the basis for a rapid, sensitive assay for biotin and avidin in solutions free of fluorescent contaminants. Avidin solutions are assayed by titration with a standard biotin solution until no further decrease in fluorescence at 350 nm, with excitation at 290 nm. is observed. Unknown quantities of biotin in solution may be determined by titration with aliquots of standard avidin until the change in fluorescence observed following each addition undergoes a sharp increase. As little as 20 ng of biotin may be measured in this way.