The use of a superconducting magnetometer to measure spin equilibria in hemoglobin

We are very glad to have the opportunity to outline the outcome of so many years of happy collaboration in this volume to honour Prof. Giorgia Careri. Indeed it is quite appropriate to do so. Even if the reader will not find referenced any paper in collaboration with him, still his role in this work has been just as great and relevant. It is thanks to Prof. Careri that one of us (M.C.) was at first introduced to the world of superfluidity and superconductivity and then to biophysics. Superconducting electronics, with SQUIDs etc., was offering good opportunities for the developement of susceptometers sensitive and accurate enough for biological studies. The first such efforts were carried out in Jim Mercereau's laboratory in Caltech by E. Hoenig and Run Han Wang. One of the authors, M.C., following the style of Careri's laboratory, had the opportunity to spend one year doing research abroad in an outstanding laboratory. As he had been using SQUIDs for high resolution magnetic studies in solid state physics and wantend to expand his studies to biological matter, he chose to go to Caltech, where he also developed his interest in hemoglobin. Afterwards, in Careri's laboratories in Rome and Monterotondo, SQUID susceptometers were developed, with which the authors carried out the first experiment on ferric hemoglobin with Max Perutz. These studies have been pursued up to the present, even after M.C.'s laboratory moved to Trento. Therefore, we would like to thank Prof. Giorgio Careri for creating the opportunity by which we have been able to enjoy this collaboration for all these years.