Biocytin hydrazide derivative

Prepare the labeling reagent stock solution. Biotin, biocytin, and desthiobiotin hydrazide derivatives are typically used at a labeling reagent antibody MR of 20-25. Biotin and desthiobiotin hydrazide stock solutions should be prepared at 10-20 mg/mL in DMSO or DMF while biocytin hydrazide can be dissolved in the reaction... 

First, examples of fluorescence [235] and chemiluminescence-based biosensors [236], derived fix)m PTs, were reported by Tripathy and coworkers. Later, the synthesis of 119 containing pendant biotin units was described. A water-soluble copolymer 120 with sulfonate and biotin in the side chains [237] exhibits a deep violet color (Amax = 550 run) which turns yellow (A ax = 400 nm) on binding with avidin. An extension of this work based on the homopolymer 121 involved the preparation of monolayers of a biotinylated PT on an aminosilane-treated ITO surface by successive deposition of 121 and biocytin hydrazide in electrostatic interactions [238,239]. This ultrathin film modified electrode was shown to detect femtomoles of avidin in aqueous solution. Electrochemical and optical evidences for avidin binding were reported for a copolymer based on poly(terthiophene) 122 [240] and for the homopolymer 123 [198]. 

A protein-binding assay (BA) coupled with hplc provided a highly sensitive post-column reaction detection system for the biologically important molecule biotin and its derivative biocytin, biotin ethylenediamine, 6-(biotinoylamino) caproic acid, and 6-(biotinoylamino)caproic acid hydrazide (71). This detection system is selective for the biotin moiety and responds only to the class of compounds that contain biotin in their molecules. In this assay a conjugate of streptavidin with fluorescamine isothiocyanate (streptavidin—FITC) was employed. Upon binding of the analyte (biotin or biotin derivative) to streptavidin—FITC, an enhancement in fluorescence intensity results. This enhancement in fluorescence intensity can be directly related to the concentration of the analyte and thus serves as the analytical signal. The hplc/BA system is more sensitive and selective than either the BA or hplc alone. With the described system, the detection limits for biotin and biocytin were found to be 97 and 149 pg, respectively. 

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