Ultrastructural detection of lectin receptors by cytochemical affinity reaction using mannan-iron complex

Post-embedding cytochemistry with gold-labelled reagents: a review

The detection of antigens and glycoconjugates with the protein A-gold and the lectin-gold techniques, respectively, is reviewed. Special attention is directed to the necessary conditions for fixation and embedding as well as to the staining procedures of tissue sections for light and electron microscopy.

Ultrastructural visualization of concanavalin A binding sites using alkaline phosphatase-labeled Con A and ultrathin glycol methacrylate sections

A method for the visualization of concanavalin A (Con A) binding sites by electron microscopy of glycol methacrylate sections is presented. This method, which is an application of the alkaline phosphatase-labeled Con A conjugate technique, solves the problems not only of limited penetration of chemicals into tissue blocks but also of injuries to tissue sections due to irritative reagents experienced in Con A-peroxidase staining. Glycol methacrylate sections are incubated successively with an alkaline phosphatase-labeled Con A solution and a lead citrate medium for the enzyme activity. Different kinds of tissues from adult rats have been used to test the method; tracheal cartilage, aorta and jejunum. The localization of Con A binding sites demonstrated by this method is consistent with the results of other published studies. Appropriate controls have been performed (ie., omission of the conjugated lectin, lectin plus its inhibitor) and these substantiate the specificity of the method.

Cytochemical localization of surface carbohydrates on mycoplasma membranes

Surface carbohydrate structures, containing alpha-D-glucosyl or sterically closely related residues, were visualized on mycoplasma membranes by cytochemical staining procedure with concanavalin A and iron-dextran complexes.

Glycoproteins and polyanions in the synapses of rat and mouse central nervous system

In the present work, it is investigated the location and characteristics of receptors for Con A in synapses of rat and mouse central nervous system. Negatives charges of synaptic surface are also studied. It is observed the presence of glycoproteins on synaptosomal plasma membrane. Presence of negatives charges homogenously distributed all over the synaptosome surface is also notice. These negative charges are revealed by Colloidal Iron, FeOH++cation and cationized Ferritin. Enzymatic extraction experiments suggest that presence of sulphated mucopolysaccharides.

Detection of concanavalin A receptors by affinity to peroxidase and iron dextran by scanning and transmission electron microscopy and x-ray microanalysis

A method of cell surface mapping has been developed on spermatozoa. Concanavalin A binding sites have been simultaneously revelaed both by peroxidase DAB reaction and by iron dextran coupling. The areas are examined in scanning and transmission electron microscopes and submitted to electron probe X-ray microanalysis.

Heavy metal carbohydrate complexes for demonstration of lectin surface receptors. The preparation of a galactan-iron complex

The preparation of a galactan-iron complex is described. The galactan iron complex can be used for electron microscopic demonstration of membrane bound Ricinus communis lectin because the high reactivity of this lectin toward the galactan.

Wheat germ agglutinin and Ticinus communis agglutinin as specific saccharide stains in light and electron microscopy

Two plant agglutinins, wheat germ agglutinin and Ricinus communis agglutinin, were used for light and electron microscopic detection of certain carbohydrate-containing cell surface components and extracellular polysaccharides. For light microscopic studies on various tissues fluorescein isothiocyanate coupled lectins were prepared. The ferritin coupling of the lectins for electron microscopy was performed by glutarldehyde in the presence of the specific hapten. The specificity of the reactions was demonstrated by blocking with the hapten.