Anti-Biotin Recombinant Mouse mAb (S-5555)

As a labeling agent, the core value of Biotin lies in exploiting the extraordinarily strong non-covalent binding between biotin and avidin or streptavidin (with dissociation constants on the order of 10⁻¹⁵ M): biotin is covalently conjugated to antibodies, nucleic acid probes, or other target molecules, and detection or capture is then achieved using avidin/streptavidin conjugated to enzymes, fluorophores, or colloidal gold, thereby enabling signal amplification and specific tracing. Because the biotin molecule is very small (approximately 244 Da), labeling usually does not significantly interfere with the biological activity or binding capacity of the target molecule. This system is widely used in enzyme-linked immunosorbent assays, immunoblotting, immunohistochemistry, and lateral flow strip tests: in nucleic acid detection strips, for example, amplification products are labeled with both biotin and fluorescein—biotin immobilizes the product on the streptavidin test line, while fluorescein binds colorimetric particles to generate a visible signal. However, in practical design, care must be taken that excessively high biotin labeling density may cause steric hindrance and actually weaken streptavidin binding efficiency.