A chelating agent useful for the determination of calcium in the presence of magnesium, Ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid has been used in Dulbecco′s phosphate-buffered saline (DPBS) to induce the weakening of cell-to-cell junctions and as a component in lysis buffer for lysing mouse mucosal cells for western blot analysis.