Lectins are glycan-binding proteins that have been purified from trees, beans and certain fruits. They are very specific for a given glycan according to their sequence and the different sugar unit structures that the glycan contains. 

Lectins can be classified into several groups according to their ability to bind to glycans, for example, fucose-binding lectins (AAL etc.), sialic acid-binding lectins (SNA etc.), galactose-binding lectins (ECA etc.), mannose-binding lectins (GNA etc.), O-glycan-binding lectins (Jacalin etc.), branching structure-binding lectins and others. The appropriate choice of a range of lectins allows to validate the structure of glycans in a short time.

Lectin arrays provide a powerful new tool for glycosylation determination, drug discovery and biomarker development; all with limited sample volumes.