Biomaterial Database

In vitro calibration of the equilibrium reactions of the metallochromic indicator dye antipyrylazo III with calcium. 1987

S Hollingworth, and R W Aldrich, and S M Baylor

The equilibrium reactions of the metallochromic indicator dye Antipyrylazo III with calcium at physiological ionic strength have been investigated spectrophotometrically. Dye absorbance as a function of wavelength was measured at various total dye and calcium concentrations. Analysis of the absorbance spectra indicated that at pH 6.9 at least three calcium:dye complexes form, with 1:1, 1:2, and possibly 2:2 stoichiometries. The dissociation constant and the changes in dye extinction coefficients on formation of the 1:2 complex, the main complex which forms when Antipyrylazo III is used to study cytoplasmic calcium transients, have been characterized.

UI	MeSH Term	Description	Entries
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D009282	Naphthalenesulfonates	A class of organic compounds that contains a naphthalene moiety linked to a sulfonic acid salt or ester.
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D013053	Spectrophotometry	The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.