Separation of individuals of any blood group into secretors and non-secretors by use of a plant agglutinin (lectin).

By WILLIAM C. BOYD AND ELIZABETH SHAPLEIGH F OR THE DIAGNOSIS of secretors amid non-secretors it is customary to use anti-A or anti-B agglutimiating sera, depending on the blood group of the person being tested. In many investigations, no attempt is made to separate the individuals of group 0 imito secretors and non-secretors, although it was shown9 that the absorbed sera of certaimi cattle, or the serum of a goat injected w ith Shiga bacillus,’0 would enable the diagnosis to be made with saliva from imidividuals of group 0. The preparation of a suitable absorbed cow serum is not easy, amid the sera of mamiy cattle do not possess the proper agglutinins; furthermore, goat anti-Shiga sera of the proper specificity are not readily available. Grubb7 has shown that the serum of some eels contain an anti-H, but only a few ml. of blood are obtainable from an eel, and the agglutinin is not found in all eels. Simice Schiff’#{176}observed that the absorbed cow serum and the goat anti-Shiga serum studied by him could serve for the diagnosis of secretors, not only of group 0 but of any of the other groups, it is apparent that if such reagents were routimiely available the procedure of diagnosing secretors would be appreciably simplified. The sera found suitable for the separation of group 0 individuals into secretors amid non-secretors were called by Schiff anti-O sera, but it is apparent that imi reality they contained agglutinimis of the type which Morgan and Watkins8 propose to call anti-H. When we found,6 therefore, that an extract of the seeds of Ulex europeus contained an anti-H agglutinmn* of fair strength, it occurred to us to test the suitability of this reagent for the diagnosis of secretors. The present communicatiomi is a report of these experiments. The anti-H character of the Ulex agglutimiin is shown in table 1. The extract was made by miximig the seeds, ground to meal in a mill, with ten times their weight of 0.9 per cent saline, iii a shakimig machine for an hour, centrifuging and filterimig. The stock solution was kept in the deep freeze and thawed as needed. The inhibition of the agglutinin in the Ulex extract by saliva from secretors and non-secretors of various groups, compared with the inhibition observed with the usual reagents, is shown in table 2. The anti-A and anti-B reagents