Constant current chronopotentiometric peak H at mercury electrodes was recently shown as a sensitive tool for global and local changes in protein conformation . Large differences between the heights of peak H of native (hBSA(nat)) and denatured BSA (hBSA(den)) were observed. The ratio hBSA(den)/hBSA(nat) increased with more negative stripping current suggesting that the rate of potential change is important for discrimination between native and denatured BSA. Voltammetric peaks of BSA were less well developed and BSA(den)/BSA(nat) was much smaller. It was not possible to discriminate BSA(den) and BSA(nat) using carbon electrodes.