Biotin-avidin systems can be used as an alternative to indirect antibody sandwich methods in the detection of T lymphocyte subsets in cryostat sections of human lymphoid tissue. Appreciable endogenous avidin binding activity (EABA) has been found, however, in human lymph nodes and tonsils. Such EABA can be a source of false positive staining when biotin-avidin detection systems are used to iden...

The binding between biotin and streptavidin or avidin is one of the strongest known non-covalent biological interactions. The (strept)avidin-biotin interaction has been widely used for decades in biological research and biotechnology. Therefore labeling of purified proteins by biotin is a powerful way to achieve protein capture, immobilization, and functionalization, as well as multimerizing or...

We report the first use of differential terahertz time-domain spectroscopy for bioaffinity sensing. Binding is observed by measuring the transmission of a thin layer of biotin bound to the sensor protein avidin. We demonstrate the THz wave transmission of a sub-micron-thick film and sensitivity to 0.1 microg cm(-2) of biotin. These results point the way for a host of biosensor applications usin...

Catalytic activity of the filamentous polymeric form of avian liver acetyl-CoA carboxylase, (spO+ = 45 to 47 S) undergoes first-order decay in assay reaction mixture (f; 10 min at Z”), which is rapidly reversed ( <lO s) by addition of tricarboxylic acid activator, i.e. citrate or isocitrate. As previously shown by sucrose density gradient centrifugation, extended exposure to assay reaction mixt...

Precise and high-resolution coupling of functional proteins with micro-transducers is critical for the manufacture miniaturized bioelectronic devices. Moreover, electrochemistry on microelectrodes has had a major impact electrochemical analysis sensor technologies, since small size microelectrode affects radial diffusion flux analyte to deliver enhanced mass transport electrode kinetics. Howeve...

Acetyl-CoA carboxylase catalyzes the first committed step in the synthesis of fatty acids. Because fatty acids are required during myelination in the developing brain, it was proposed that the level of acetyl-CoA carboxylase may be highest in embryonic brain. The presence of acetyl-CoA carboxylase activity was detected in chick embryo brain. Its activity varied with age, showing a peak in the 1...

There is a significant genetic component in age-related macular degeneration (AMD). CX3CR1, which encodes the fractalkine (chemokine, CX3CL1) receptor, has two single nucleotide polymorphisms (SNPs): V249I and T280M. These SNPs are correlated with other aged-related diseases such as atherosclerosis. We have reported an association of CX3CR1 SNP and AMD. In this study we examined CX3CR1 SNP freq...

A homogeneous enzyme-linked competitive-binding assay for biotin with glucose-6-phosphate dehydrogenase (GGPDH), is described. This assay is based on the interaction between a GGPDH/biotin conjugate with avidin, a natural binder for biotin. In the absence of biotin in the assay mixture, this interaction results in 100% inhibition of the enzyme conjugate. In the presence of biotin, the enzymatic...