Allura Red bound to warfarin site on bovine serum albumin (BSA).

Allura Red–BSA binding was entropically driven by fluorescence spectroscopy.

Allura Red–BSA binding was entropically and enthalpically driven by calorimetry.

Surface tension at equilibrium provided Allura Red–BSA stoichiometry.

Allura Red diffusion coefficient indicated Allura Red–BSA interaction.