Use of Fluorochrome-Labeled Lectins in Light Microscopy

The use of lectins with different carbohydrate specificitres has demonstrated that there is a great diversity of carbohydrate residues, particularly in glycoconjugates of the cell membranes, but also in (sub)terminal carbohydrate residues of mucins and then precursors stored in the mucin granules of goblet and other mucin-producing cells (1 ,2 ). The methods for the detection of these carbohydrate residues using fluorescence microscopy have mainly been carried out on cryostat or paraffin wax sections, although the use of fluorescentlabeled lectins on semithin sections is in principle possible, but not advisable owing to the lack of amplification signal. The particular advantages of using fluorochrome-labeled lectins are first, the methodology is quick and easy to perform; second, quantification of the lectin binding intensity is possible by using fluorescence-activated cell sorters (FACS) or analyzers and digital imaging processing