Two plant agglutinins were isolated and purified from Croton tiglium seeds CTA220 (mol. wt. approximately 220,000) agglutinated normal and trypsinized cell lines, but did not agglutinate swine normal and trypsinized erythrocytes. CTA88 (mol. wt. approximately 88,000) agglutinated swine red blood cells. However it did not agglutinate rabbit normal blood cells. The agglutination effect could be observed for rabbit blood cells after trypsinization. The agglutinins agglutinated trypsinized cells at much lower con-centrations than those required to agglutinate normal cell lines. The implication of the change in agglutinability of the trypsinized cell was discussed in relation to the topology of the cell surfaces. 由巴豆種子中分離出的兩種凝集素CTA220(分子量約220,000 )及CTA88 (分子量約88,000 )，試驗其對正常細胞及變形細胞的凝集作用，結果:
1.CTA220對豬的紅血球無凝集作用，但對其他動物的血液有凝集反應，尤其對兔子的紅血球具有最強的凝集現象。CTA88只對豬的紅血球有凝集反應，而對其他種的血球則無作用。
2. CTA220對經由胰蛋白處理後變形的豬紅血球仍無凝集作用。但是CTA 88則對經由胰蛋白處理後的兔紅血球轉變成具有強烈的凝集反應。
