The fractional saturation of hemoglobin with oxygen was plotted agains
t P/P-50 and the slope of the abscissa at 1 was calculated for 38 OEC
data sets of human Hb A, There was a linear correlation between the sl
ope and the Hill coefficient (n(max)), and the slope was about one-for
th that of n(max). This implies that the slope of the abscissa at 1 of
Y vs P/P-50 plot can provide information about the magnitude of coope
rativity in hemoglobin oxygen binding.