A study of the purification and properties of ricin.

Ricin, the highly toxic, hemagglutinating protein of the castor bean, has always been of great interest to the chemist and the immunologist (l-4), partly because it, may readily be obta.ined in considerable quantities. Earlier methods of preparation were carried out before the development of modern physicochemical and immunochemical methods for characterizing proteins and data are therefore lacking on the purity and homogeneity of the products obtained. In the present report a summary is given of a portion of a study carried out during 1943-45 in consultation and collaboration with other laboratories engaged in parallel investigations which, it is hoped, will soon be published. Since results and materials were freely exchanged, some of the data included here were obtained on material from other laboratories, as indicated in the text.