Fluorescence labeling and microscopic imaging of colonic mucosal transformations

The aim of this work was to develop an efficient fluorescence microscopic technique and selective fluoroprobes for cancer diagnosis in colon tissue sections, as well as to determine the morphological components where selective dye accumulation has occurred. For this purpose a novel fluorescence probe, Rh B - phenyl boronic acid was synthesized and examined. This derivative distinguished clearly and consistently, healthy from neoplastic human colon tissue sections. Intense accumulation was observed at the amorphous material in the lumen of neoplastic crypts, of the colonic epithelium. To gain insight into the localization pattern of this fluoroprobe and to correlate it with mucin alterations, mucicarmine and the blue-fluorescent conjugate of wheat germ agglutinin (WGA) with Alexa 350 were used. Alexa 350 -WGA reacted primarily with mucin secreted in the malignant crypt lumen suggesting that this material is rich in sialic acid and N-acetylglucosaminyl residues.