ABSTRACT

Lectins are proteins or glycoproteins of plant, animal, or bacterial origin that bind to cell surfaces through specific carbohydrate-containing receptor sites. They are of non-immune origin. Because of this unique property, as well as because of the possession of two or occasionally more binding sites in their molecular configuration, lectins have been widely used as probes for cell surface (in animals) and cell wall (in plants) studies in the localization and identification of carbohydrate molecules. Several lectins are now known but only a few of them have been exploited for marking cell wall carbohydrates. Therefore, for cytochemistry they must be tagged onto a probe that can be visibly seen. Although lectin probes offer interesting possibilities in cell wall carbohydrate cytochemistry, many problems are to be sorted out. The first is the specificity of the lectin probe to be used. The second pertains to the ease of penetration of lectins into specimens.