Chitosan-colloidal gold complexes as polycationic probes for the detection of anionic sites by transmission and scanning electron microscopy

1988 ◽  
Vol 90 (3) ◽  
pp. 165-175 ◽  
Author(s):  
M. Horisberger ◽  
M.-F. Clerc
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Colloidal Gold ◽  
Anionic Sites ◽  
Gold Complexes ◽  
Scanning Electron

scholarly journals Effective diameters of protein A-gold and goat anti-rabbit-gold conjugates visualized by field emission scanning electron microscopy.

1992 ◽  
Vol 40 (6) ◽  
pp. 751-758 ◽  
Author(s):  
P Lea ◽  
D K Gross
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Field Emission ◽  
Gold Particle ◽  
Protein A ◽  
Gold Complexes ◽  
Gold Particles ◽  
Gold Particle Size ◽  
Scanning Electron

High-voltage (15-30 kV) field emission scanning electron microscopy (FESEM) was used to evaluate the effects of gold particle size and protein concentration on the formation of protein-gold complexes. Six colloidal gold sols were prepared, ranging in diameter from 7.6 to 39.8 nm. The minimal protecting amounts (m.p.a.) of protein A and goat anti-rabbit antibody (GAR) were experimentally determined. Gold particles were conjugated at the m.p.a., one half the m.p.a., and ten times the m.p.a. for both proteins, and protein-gold complexes prepared for FESEM. The smallest colloidal gold particles required the most protein per milliliter of gold suspension for stabilization. Transmission electron microscopy was found to be the preferred method for accurate sizing of gold particles, whereas FESEM of protein-gold complexes permitted visualization of a protein halo around a spherical gold core. Protein halo width varied significantly with changes in gold particle size. Measurements of protein halos indicated that conjugation with the m.p.a. of protein A resulted in the thickest protein layers for all gold sizes. GAR conjugation with the m.p.a. again produced the thickest protein layers. However, GAR halos were significantly smaller than those obtained with protein A conjugation. The proteins used showed similar adsorption patterns for the larger gold particles. For smaller gold particles, proteins may act differently, and these complexes should be further characterized by low-voltage FESEM.

Immuno-scanning electron microscopic localization of extracellular wood-degrading enzymes within the fibrillar sheath of the brown-rot fungus Postia placenta

1992 ◽  
Vol 38 (9) ◽  
pp. 898-904 ◽  
Author(s):  
Frederick Green III ◽  
Carol A. Clausen ◽  
Michael J. Larsen ◽  
Terry L. Highley
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Monoclonal Antibodies ◽  
Colloidal Gold ◽  
Brown Rot ◽  
Postia Placenta ◽  
Degrading Enzymes ◽  
Brown Rot Fungus ◽  
Hyphal Sheath ◽  
Scanning Electron

Extracellular wood-degrading enzymes of the brown-rot fungus Postia placenta were localized using colloidal gold labeled monoclonal antibodies to the β-1,4-xylanase (32 to 36 kDa) fraction of P. placenta. Postia placenta was grown from agar onto glass cover slips, immunolabeled with or without prior fixation, and examined by scanning electron microscopy. Enzymes were localized on the hyphal surface and on the clumped fibrillar elements mycofibrils of the hyphal sheath following fixation with glutaraldehyde. If fixation was omitted, labeling was diffuse and not localized on individual or clumped mycofibrils. We conclude that extracellular decay enzymes are weakly bound (noncovalently) to, but not identical with, the linear mycofibrillar elements of the hyphal sheath. The linear structural elements of the hyphal sheath may play an important role in transport and presentation of wood-degrading enzymes during the decay process. Key words: brown-rot fungi, enzymes, mycofibrils, hyphal sheath, immunolabeling, monoclonal antibodies, colloidal gold, scanning electron microscopy.

A Review on Colloidal Gold Post-Embedding Cytochemical Techniques

1985 ◽  
Vol 43 ◽  
pp. 422-425 ◽  
Author(s):  
Moïse Bendayan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Binding Sites ◽  
Colloidal Gold ◽  
Short Review ◽  
Antigenic Sites ◽  
Affinity Techniques ◽  
Intracellular Binding ◽  
Dense Marker ◽  
Scanning Electron

In 1971, colloidal gold was introduced in immunocytochemistry by Faulk and Taylor for the ultrastructural demonstration of antigenic sites at the surface of bacteria. Since then, application of this marker has been growing rapidly, extending its use to the various fields of cytochemistry. Indeed, it has been applied for pre- and post-embedding labeling of cell surface and intracellular binding sites respectively. It has been used in light microscopy as well as in both transmission and scanning electron microscopy, and thus appears today as the marker of choice in cytochemistry.The present short review means to illustrate four different affinity techniques, which have been developed recently for the ultrastructural postembedding localization of various macromolecules using colloidal gold as the electron dense marker.

scholarly journals A novel approach for scanning electron microscopy of colloidal gold-labeled cell surfaces.

1984 ◽  
Vol 99 (1) ◽  
pp. 53-57 ◽  
Author(s):  
E de Harven ◽  
R Leung ◽  
H Christensen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Surface ◽  
Colloidal Gold ◽  
Protein A ◽  
Staphylococcal Protein A ◽  
Good Resolution ◽  
Novel Approach ◽  
Backscattered Electron ◽  
Scanning Electron

A method is described for the use of scanning electron microscopy on the surface of gold-labeled cells. It includes the use of 45- or 20-nm colloidal gold marker conjugated with Staphylococcal protein A. The marker is best recognized on the basis of its atomic number contrast by using the backscattered electron imaging mode of the scanning electron microscope. When the backscattered electron signal is mixed with the secondary electron signal, an optimum correlation between the distribution of the labeled sites and the cell surface structures is demonstrated. The method is illustrated by its application to the identification of human circulating granulocytes. Its good resolution, high contrast, and good labeling efficiency offers a promising approach to the specific localization of cell surface antigenic sites labeled with particles of colloidal gold.

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