The oxygen equilibrium of fetal and adult human hemoglobin.

Although the fetal and adult hemoglobins of many species, including man, are essentially similar in molecular weight and in spectroscopic characteristics, they exhibit marked differences in other chemical and physical properties (l-6). Therefore, they may be assumed to represent distinct chemical entities. The present study was undertaken to determine whether the chemical difference is expressed in variation of oxygen equilibria. The oxygen equilibrium of hemoglobin is conveniently characterized in terms of Hill’s equation