Occurrence and isolation

The simplest way to detect the presence of a lectin in a biological material is to prepare a water or buffer extract from this material and to examine its ability to agglutinate erythrocytes or to precipitate a polysaccharide or glycoprotein. If a positive result is obtained, it is essential to show that agglutination or precipitation is specifically inhibited by mono- or oligosaccharides, i.e. it is sugar specific (Fig. 3.1).