AnaSpec is pleased to announce
the availability of our new HABA Biotin Quantitation Kits. These kits provide
a convenient method for estimating the molar ratio of biotin to protein on
biotinylated conjugates. They can also be used to quantitate the biotin concentration
in a solution.
Available in two convenient
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 labeling proteins with biotin
a useful tool for applications such as affinity chromatography and immunoanalytical
assays.
The assay utilizes 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 348 nm,
while the HABA/avidin complex has strong absorption at 500 nm. Since the affinity
between HABA and avidin is relatively weak (Kd=5.8 x 10-6
M) compared to the affinity between biotin and avidin (Kd=1 x 10-15
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 to 16 mM.
Click
here to request AnaSpec’s Detection Reagents & Assay Kits catalog.
Related Products and Services:
Streptavidin
conjugated to HiLytePlusTM dyes
Streptavidin conjugated
to HiLyte FluorTM dyes
Custom
synthesis of biotin conjugated peptides
