Preparation of Antigens Containing Carbohydrate Residues

Polysaccharides from plants have been prepared by a number of methods. Polysaccharides are present in the seeds45 of the plant or in exudates46-463 of shrubs. If seeds are used, it is necessary to grind the seed before extraction of the polysaccharides. Extraction by distilled water or a suitable buffer is used. The extracts so obtained may contain a small amount of flocculent material, which is allowed to settle and is removed by centrifugation. The supernatant solution is then treated with several volumes of 95% alcohol. A white precipitate of the polysaccharide is formed, and this precipitate is collected by centrifugation. The precipitate is dehydrated with absolute 

A second sample of the tumor tissue is extracted with KC1-HC1 solution (0.05 M KC1 and 0.01 M HC1 of pH 2). First the tissue is homogenized in two volumes of the KC1-HC1 solution in a Waring blender for 15 min. This homogenate is subjected to a treatment similar to that for the perchloric acid homogenate. An extract of normal tissue is also prepared by the KC1-HC1 method. 

---