What Is a Biotin Antibody?

Biotin-Avidin-System (BAS) is a new biological reaction amplification system developed in the late 1970s. With the advent of various biotin derivatives, BAS was soon widely used in various fields of medicine. A large number of studies in recent years have confirmed that the biotin-avidin system can be combined with almost all kinds of markers successfully studied. The strong affinity of biotin and avidin and the multi-stage amplification effect make BAS immunolabeling and related tracer analysis more sensitive. It has become a new technology widely used for trace antigen, antibody qualitative, quantitative detection and localization observation research.

Biotin-avidin system

Biotin (B) is widely distributed in animal and plant tissues, and is often extracted from higher yolk and liver tissues with a molecular weight of 244.

The great advantages of BAS in practical applications are mainly reflected in the following aspects.

Biotin-Avidin System Sensitivity

Biotin is easily combined with biological macromolecules such as proteins and nucleic acids, and the biotin derivative formed not only maintains the original biological activity of the macromolecular substance, but also has a higher specificity and is multivalent. In addition, each avidin molecule has four biotin binding sites, which can simultaneously bind biotinylated macromolecular derivatives and labels in a multivalent form. Therefore, BAS has a multi-stage amplification effect, which can greatly improve the sensitivity of the detection method in application.

Biotin-avidin system specificity

The binding between avidin and biotin has a very high affinity, and the response is highly specific. Therefore, the multi-level amplification of BAS does not increase non-specific interference while increasing sensitivity. Moreover, the binding characteristics of BAS are not affected by the high dilution of the reaction reagent, which makes it possible to minimize the non-specific effect of the reaction reagent in practical applications.

Biotin-avidin system stability

The affinity constant of avidin-binding biotin can be one million times that of the antigen-antibody reaction. The dissociation constant of the two to form a complex is very small, showing irreversible reactivity; and Neither the organic solvents affect their binding. Therefore, in practical applications, BAS has high product stability, which can reduce operating errors and improve measurement accuracy.

Universality of biotin-avidin system

The versatility of the biotin-avidin system also provides a unified approach to research. For example, for a molecule to be tested, a biotin-labeled antigen for the molecule has been obtained, then colloidal gold combined with avidin can be observed under an electron microscope, and avidin combined with a fluorescent label can be screened by flow cytometry. Avidin linked to the enzyme can be used for immunohistochemical experiments such as ELISA.

Biotin-avidin system other

BAS can be made into a variety of versatile reagents (such as biotinylated secondary antibodies, etc.) according to specific experimental method requirements, which are suitable for different reaction systems, and can be highly diluted, with small amounts, and low experimental costs; especially BAS and costs The use of high antigen-specific primary antibodies can greatly reduce the amount of the latter and save experimental costs. In addition, because the combination of biotin and avidin has the characteristics of high speed and high efficiency, although the response level of BAS is more, the incubation time required is not long, and the experiment can be completed in only a few hours.