Haba Biotin quantitation kits provide a convenient method for estimating the molar ratio of biotin to protein on biotinylated conjugates
AnaSpec's new line of Haba Biotin quantitation kits can also be used to quantitate the biotin concentration in a solution.
Available in two sizes:.
120 Assays 72096-120 (120 assays in a 96-well format or 25 assays in a cuvette format).
500 Assays 72096-500 (500 assays in a 96-well format or 100 assays in a cuvette format).
Biotin and avidin (or streptavidin) bind non-covalently with a higher binding affinity than most antigen-antibody interactions.
This very tight binding makes labelling proteins with biotin a useful tool for applications such as affinity chromatography and immunoanalytical assays.
The assay utilises the observation that Haba (4'-hydroxyazobenzene-2-carboxylic acid) shows dramatic spectral changes when it binds to avidin.
Free Haba has an absorption peak at 348nm, while the Haba/avidin complex has strong absorption at 500nm.
Since the affinity between Haba and avidin is relatively weak (Kd=5.8 x10-6 M) compared to the affinity between biotin and avidin (Kd=1 x10-15 M), biotin can easily replace Haba from the Haba/avidin complex, resulting in a decrease of absorption at 500 nm.
Avidin and Haba at an optimal ratio are included in the assay kit.
The kit has a linear range of 2-16mM.
