A Preliminary Note on the Preparation of Anti-Rh Agglutinin

The test serum for detecting the Rh antigen in the red cells of the human population may be prepared according to the technique originally described by Landsteiner and Weiner (1941) by the injection of red cells from the Rhesus monkey into . guinea-pigs or rabbits. As in other immunological experiments, only a few of the animals thus treated yield a satisfactory anti-serum. Even then, the action of such a serum is complicated by the presence of groupagglutinins which in an undiluted state generally agglutinate human red cells of all groups. To eliminate the false positive reactions, serum thus prepared is diluted with normal saline. The amount of dilution required to eliminate false positive reactions is variable, so that each batch of serum has to be standardized against a known standard. Sera of mothers giving birth to children suffering from erythroblastosis-fcetalis are, in many cases, good sources of potent anti-Rh agglutinins, and serve as standards for the test serum prepared by immunizing rabbits or guinea-pigs. For reasons not fully understood, very few case^ of erythroblastosis-fcetalis are reported here 'in India, and so far maternal serum of such cases has not been available. While thinking of some means of obtaining the test serum from the animals in a more purified form, I wondered if purified anti-Rh agglutinins could be obtained by employing the technique described by Landsteiner and Miller (1925), for obtaining purified anti-A and anti-B agglutinins. Experiments were, therefore, undertaken to find out if purified anti-Rh agglutinin could be prepared in the same way, by first producing anti-Rh agglutinin in a susceptible animal by injection of red cells from a rhesus monkey, later absorbing the anti-Rh agglutinin with cells, and finally dissociating the agglutinin from the cells at a higher temperature. Method.?Washed red cells of rhesus monkeys