The lysosomal storage material in cultured fibroblasts from patients with various
lysosomal storage diseases was characterized by fluorescence microscopy using
lectins specific for different saccharide moieties. In normal fibroblasts and cultured amniotic fluid cells
lectins specific for mannosyl and glucosyl moieties, Con A and LcA gave a bright perinuclear cytoplasmic staining corresponding to the localization of endoplasmic reticulum in the cells. All other
lectins stained the Golgi apparatus as a juxtanuclear reticular structure. In
fucosidosis fibroblasts, only
lectins specific for fucosyl groups LTA and UEA, distinctly stained the lysosomal inclusions. The lysosomes in
mannosidosis fibroblasts did not react with Con A and LcA, both specific for mannosyl moieties of
glycoconjugates, but were brightly labeled with WGA, a
lectin specific for N-acetyl glucosaminyl moieties. In I-cell fibroblasts, the numerous perinuclear phase-dense granules, representing abnormal lysosomes, were labeled with every
lectin used. In fibroblasts from patients with
Salla disease, a newly discovered lysosomal storage disorder, the lysosomes were brightly stained only with LPA, indicating the presence of increased amounts of
sialic acid residues in the lysosomal inclusions.