Fluorescein Binding to Normal Human Serum Proteins Demonstrated by Equilibrium Dialysis

Abstract

• The binding of fluorescein to normal human serum proteins in a physiologic solvent at 37 °C was measured by equilibrium dialysis. Human serum contained 3.28 x 10^-3M concentration fluoresceinbinding sites, with an average association constant at 37 °C of 0.54 X 10⁴M^-1. The percentage of total fluorescein bound by human serum proteins ranged from 83% to 53% when the total fluorescein concentration ranged from 6.9 X 10^-5 to 6.2 X 10^-3M.