Tomato lectin is a very stable glycoprotein containing about 50 percent arabinose and galactose. This lectin is composed of a single polypeptide of about 100,000 daltons that may form aggregates in solution. Like other lectins that bind N-acetylglucosamine oligomers, tomato lectin prefers trimers and tetramers of this sugar. Tomato lectin, although sharing some specificities with potato, Datura lectin and wheat germ agglutinin, has been reported to be dissimilar in many respects. Tomato lectin binds well to such glycoproteins as glycophorin and Tamm-Horsfall glycoprotein.Agarose bound* Lycopersicon Esculentum (Tomato) Lectin is prepared from affinity-purified lectin. Heat stable, cross-linked 4% agarose beads with a molecular weight exclusion limit of about 2x107 are used as the solid-phase matrix to which the lectin is covalently bound. The attachment of the lectin to the solid phase is carefully controlled in order to preserve the activity of the lectin as well as to minimize conformational changes of the bound lectin which might result in nonspecific ionic or hydrophobic interactions.