To expand the electron microscopist's options in localization and visualization, a new and general staining technique has been tested. The avidin-biotin complex serves as a coupling between the electron-dense marker, ferritin, and points of interest in biological samples. When specific cellular components are tagged with biotin, those components may be visualized with ferritin-linked avidin. Be...

Endogenous biotin or biotinylated protein binding activity is a major drawback to biotin-avidin/streptavidin detection system. The avidin/streptavidin conjugate used to detect the complex of the biotinylated secondary antibody and the primary antibody binds to endogenous biotin or biotinylated proteins leading to non-specific signals. In Western blot, the endogenous biotin or biotinylated prote...

This enzyme is remarkably sensitive to inhibition by highly purified egg white avidin, a phenomenon which can be completely prevented by inclusion of excess biotin in the assay system. Inasmuch as avidin has been found to selectively inhibit all known biotinenzymes and, indeed, is now accepted as a diagnostic tool for the detection of such reactions [2], the proposal was made that UALase belong...

BACKGROUND The quantification of surface groups attached to non-woven fibers is an important step in developing nanofiber biosensing detection technologies. A method utilizing biotin functionalized quantum dots (QDs) 655 for quantitative analysis of available biotin binding sites within avidin immobilized on electrospun nanofiber membranes was developed. RESULTS A method for quantifying nanof...

Biodegradable polymeric nanoparticles are widely recognized as efficacious drug delivery vehicles, yet the rational engineering of nanoparticle surfaces in order to improve biodistribution, reduce clearance, and/or improve targeting remains a significant challenge. We have previously demonstrated that an amphiphilic conjugate of avidin and palmitic acid can be used to modify poly(lactic-co-glyc...

The requirement of biotin in the culture medium has been established for HeLa cells, human fibroblasts, baby hamster kidney cells (BHK) as well as polyoma-transformed BHK cells. Growth, viability, biotin content and the activities of biotin-dependent enzymes were used as criteria. Cells in culture appear to bind and internalized avidin as well as the avidin-biotin complex. Avidin seems to mimic...

A method of enriching for long double-stranded segments of eukaryotic DNA carrying particular genes is described. A purified RNA coded for by the gene is covalently attached to biotin via the protein, cytochrome c. This modified RNA is hybridized to total nuclear, double-stranded DNA under conditions that allow the formation of R-loops. Avidin, which has a high affinity for biotin, is covalentl...

Multicomponent crystals and nanoparticle superlattices are a powerful approach to integrate different materials into ordered nanostructures. Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment. Here we describe the self-assembly and characterization of binary s...

Intravenously administered liposomes are versatile carriers for drugs, contrast agents, biologics, and DNA. Liposomes and other colloidal particles are currently under investigation as lymph node delivery vehicles. After s.c. injection, conventional liposomes move into the lymphatic vessels, but are poorly retained in each draining lymph node (<2% injected dose). In this report, we describe a n...

Non-covalent binding of avidin to biotinylated erythrocytes results in complement-dependent haemolysis. Biotinylated erythrocytes, as well as native cells, are not lysed by complement. Complement activation requires a tight contact between avidin and the erythrocyte membrane, since avidin does not in itself activate complement and does not inhibit lysis of sensitized sheep erythrocytes. The-eff...