The number of available C (rh', Rh 2) antigen sites within the Rh system was
estimated using trace-labelled antibody. The results, as available sites per red cell, were as
follows: CDe/CDe: 45,700-56,400; Cde/Cde: 42,200; CDe/cDE: 25,500-39,700; C^w De/cde:
21,500-40,000; Cde/cde: 31,100; CDE/cDE: 8,500-9,800; Cde/cde: 7,200. The average
equilibrium constant of the anti-C was 0.5 x 10^7 M^-1