The outer membrane protein of Neisseria gonorrhoeae was extracted with CTB in presence of CaCl2, then Protein I (P I ) was extracted with Z3, 14 and further purified by DEAE-Sepharose column chromatography.

• 在CaCl2存在下，以CTB提取淋球菌的OMP，再以Z3，14萃取PI，然后经DEAESepharoseCl－6B层析柱提纯，获得纯PI10.；97毫克。