We directly measure the electrostatic interaction between isolated pairs of microspheres (PMMA-PHSA) in solutions of surfactant (NaAOT) in oil(hexadecane). At high surfactant concentrations, we find the familiar screened Debye-Huckel form. However, at low concentrations of surfactant, we see an unscreened Coulomb potential. Our measurements extract the particle charge and solvent ionic strength. We also study the particle charge as a function of bead size.