Reexamination of the evidence for paramagnetism in oxy- and carbonmonoxyhemoglobins

Experiments have been carried out in an attempt to confirm previous reports of paramagnetism in the oxy- and carbonmonoxy derivatives of human and carp hemoglobin. When care is taken to ensure complete saturation of the hemoglobins with ligand and the diamagnetic contributions of all of the buffers are carefully evaluated, these hemoglobin derivatives are found to have the same gram susceptibilities as exhibited by a set of metal free proteins, suggesting that they are fully diamagnetic.