Thermo Scientific™ HABA (4'-hydroxyazobenzene-2-carboxylic acid), 10g

Thermo Scientific™ HABA, or 4'-hydroxyazobenzene-2-carboxylic acid, is a spectrophotometric dye reagent used to estimate the degree of biotinylation in labeled biomolecules such as proteins and antibodies. When HABA binds to avidin, it forms a yellow-orange complex with an absorbance peak at 500 nm. The presence of free biotin or biotin-labeled proteins will displace the HABA from avidin, resulting in a measurable decrease in absorbance. This allows for a simple, rapid, and reliable determination of biotin-to-protein ratios in bioconjugation workflows.

Key Features & Benefits

• Spectrophotometric Quantification: Enables direct colorimetric measurement of biotin levels at 500 nm.
• User-Friendly: Results can be calculated directly using standard absorbance values and extinction coefficients.
• Broad Compatibility: Effective over a wide range of pH and salt concentrations.
• Versatile Application: Ideal for monitoring biotin incorporation after protein biotinylation.
• Complementary Kits Available: Fully compatible with Thermo Scientific’s Biotin Quantitation Kits (e.g., 28005 and 46610).

Applications

• Biotinylation Analysis: Quantify biotin incorporation in labeled proteins or antibodies.
• Antibody Conjugation Monitoring: Validate labeling efficiency for streptavidin-based detection assays.
• Conjugation QC: Quality control step in antibody-drug conjugates (ADCs), fluorescent labeling, or affinity-tag purification workflows.
• Protein Chemistry: Validate molar ratio of biotin to protein in biochemical research or assay development.

How It Works

HABA binds to avidin forming a colored complex detectable at 500 nm. In the presence of biotin (or biotinylated proteins), HABA is displaced due to biotin’s higher binding affinity. The reduction in absorbance is proportional to the amount of biotin present. This allows the calculation of the molar amount of biotin using a standard curve or extinction coefficient calculations.

Thermo Scientific™ HABA is a cost-effective, easy-to-use reagent for quantifying biotin levels in labeled proteins. Whether used alone or as part of a comprehensive biotin quantitation kit, HABA provides rapid and accurate spectrophotometric data that supports high-quality bioconjugation, labeling, and detection workflows.