Biotin NTA

Biotin NTA (BNTA), a biotin-labeled nitrilotriacetic acid, is widely used to detect histidine-tagged proteins immobilized on nitrocellulose membranes with the detection limite of ~0.1 pmol. NTA Biotin is a bifunctional reagent that is used to detect histidine-tagged proteins immobilized. The nitrilotriacetic acid is used to chelate a Ni(II) ion at four of its six coordination sites. The remaining two sites are available for binding to a histidine tag. The NTA-polyHis-complex can be detected using standard enzyme-linked streptavidin methods, such as a streptavidin-horseradish peroxidase conjugate. Biotin NTA can be removed from the histidine-tagged protein at pH 4.8, allowing the blot to be reanalyzed with another probe. In combination with fluorescent avidin conjugates, this NTA biotin derivative can be used for detecting polyhistidine-containing biomolecules such as fusion proteins.