The variation of Romhányi's aldehyde-bisulfite-toluidine blue (ABT)-reaction: the aldehyde-bisulfite-1.9-dimethyl methylene blue (ABD)- and sialic acid specific topo-optical reaction.

The Aldehyde-Bisulfite-1.9-Dimethyl Methylene Blue reaction is a variant of Romhányi's Aldehyde-Bisulfite Toluidine Blue (ABT) reaction. The ABD reaction is also a selective topo-optical staining reaction of the vicinal (glycol) OH-groups in complex carbohydrates. According to polarization optical analysis, after the ABD-reaction we have found the oriented micellar textur of the glycoproteins in the microvillous layer of the human duodenum and jejunum. By means of the sialic-acid-specific topo-optical reaction, we have demonstrated that the sialic acid is present in an ordered form and is evenly distributed in the microvillous surface layer of duodenum and jejunum.