Demonstration of dopamine in electron-dense synaptic vesicles in the pars intermedia of Xenopus laevis, by freeze substitution and postembedding immunogold electron microscopy

1991 ◽  
Vol 96 (6) ◽  
pp. 505-510 ◽  
Author(s):  
F. J. C. van Strien ◽  
E. P. C. T. de Rijk ◽  
P. S. H. Heymen ◽  
T. G. M. Hafmans ◽  
E. W. Roubos
Keyword(s):  
Electron Microscopy ◽  
Xenopus Laevis ◽  
Synaptic Vesicles ◽  
Freeze Substitution ◽  
Immunogold Electron Microscopy ◽  
Pars Intermedia

scholarly journals Visualization of the Nuclear Lamina in Mouse Anterior Pituitary Cells and Immunocytochemical Detection of Lamin A/C by Quick-freeze Freeze-substitution Electron Microscopy

2005 ◽  
Vol 53 (4) ◽  
pp. 497-507 ◽  
Author(s):  
Takao Senda ◽  
Akiko Iizuka-Kogo ◽  
Atsushi Shimomura
Keyword(s):  
Electron Microscopy ◽  
Nuclear Membrane ◽  
Anterior Pituitary ◽  
Freeze Substitution ◽  
Nuclear Lamina ◽  
Immunogold Electron Microscopy ◽  
Lamin A ◽  
Pituitary Cells ◽  
Inner Nuclear Membrane ◽  
Anterior Pituitary Cells

We examined the nuclear lamina in the quickly frozen anterior pituitary cells by electron microscopic techniques combined with freeze substitution, deep etching, and immunocytochemistry and compared it with that in the chemically fixed cells. By quick-freeze freeze-substitution electron microscopy, an electron-lucent layer, as thick as 20 nm, was revealed just inside the inner nuclear membrane, whereas in the conventionally glutaraldehyde-fixed cells the layer was not seen. By quick-freeze deep-etch electron microscopy, we could not distinguish definitively the layer corresponding to the nuclear lamina in either fresh unfixed or glutaraldehyde-fixed cells. Immunofluorescence microscopy showed that lamin A/C in the nucleus was detected in the acetone-fixed cells and briefly in paraformaldehyde-fixed cells but not in the cells with prolonged paraformaldehyde fixation. Nuclear localization of lamin A/C was revealed by immunogold electron microscopy also in the quickly frozen and freeze-substituted cells, but not in the paraformaldehyde-fixed cells. Lamin A/C was localized mainly in the peripheral nucleoplasm within 60 nm from the inner nuclear membrane, which corresponded to the nuclear lamina. These results suggest that the nuclear lamina can be preserved both ultrastructurally and immunocytochemically by quick-freezing fixation, rather than by conventional chemical fixation.

scholarly journals Immunogold electron microscopy of phytochrome in Avena: identification of intracellular sites responsible for phytochrome sequestering and enhanced pelletability.

1986 ◽  
Vol 103 (6) ◽  
pp. 2541-2550 ◽  
Author(s):  
D W McCurdy ◽  
L H Pratt
Keyword(s):  
Electron Microscopy ◽  
Red Light ◽  
Freeze Substitution ◽  
Immunogold Labeling ◽  
Immunogold Electron Microscopy ◽  
Subcellular Component ◽  
Discrete Structures

Using monoclonal antibodies to the plant photoreceptor, phytochrome, we have investigated by immunogold electron microscopy the rapid, red light-induced, intracellular redistribution (termed "sequestering") of phytochrome in dark-grown Avena coleoptiles. Pre-embedding immunolabeling of 5-micron-thick cryosections reveals that sequestered phytochrome is associated with numerous, discrete structures of similar morphology. Specific labeling of these structures was also achieved by post-embedding ("on-grid") immunostaining of LR-White-embedded tissue, regardless of whether the tissue had been fixed chemically or by freeze substitution. The phytochrome-associated structures are globular to oval in shape, 200-400 nm in size, and are composed of amorphous, granular material. No morphologically identifiable membranes are present either surrounding or within these structures, which are often present as apparent aggregates that approach several micrometers in size. An immunogold labeling procedure has also been developed to identify the particulate, subcellular component with which phytochrome is associated in vitro as a consequence of irradiation of Avena coleoptiles before their homogenization. Structures with appearance similar to those identified in situ are the only components of the pelletable material that are specifically labeled with gold. We conclude that the association of phytochrome with these structures in Avena represents the underlying molecular event that ultimately is expressed both as red light-induced sequestering in vivo and enhanced pelletability of phytochrome detected in vitro.

scholarly journals Colocalization of synapsin and actin during synaptic vesicle recycling

2003 ◽  
Vol 161 (4) ◽  
pp. 737-747 ◽  
Author(s):  
Ona Bloom ◽  
Emma Evergren ◽  
Nikolay Tomilin ◽  
Ole Kjaerulff ◽  
Peter Löw ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Synaptic Vesicle ◽  
Active Zone ◽  
Synaptic Vesicles ◽  
Synaptic Activity ◽  
Immunogold Electron Microscopy ◽  
Synaptic Vesicle Recycling ◽  
Vesicle Recycling ◽  
Reserve Pool ◽  
Giant Synapse

It has been hypothesized that in the mature nerve terminal, interactions between synapsin and actin regulate the clustering of synaptic vesicles and the availability of vesicles for release during synaptic activity. Here, we have used immunogold electron microscopy to examine the subcellular localization of actin and synapsin in the giant synapse in lamprey at different states of synaptic activity. In agreement with earlier observations, in synapses at rest, synapsin immunoreactivity was preferentially localized to a portion of the vesicle cluster distal to the active zone. During synaptic activity, however, synapsin was detected in the pool of vesicles proximal to the active zone. In addition, actin and synapsin were found colocalized in a dynamic filamentous cytomatrix at the sites of synaptic vesicle recycling, endocytic zones. Synapsin immunolabeling was not associated with clathrin-coated intermediates but was found on vesicles that appeared to be recycling back to the cluster. Disruption of synapsin function by microinjection of antisynapsin antibodies resulted in a prominent reduction of the cytomatrix at endocytic zones of active synapses. Our data suggest that in addition to its known function in clustering of vesicles in the reserve pool, synapsin migrates from the synaptic vesicle cluster and participates in the organization of the actin-rich cytomatrix in the endocytic zone during synaptic activity.

scholarly journals Improved Procedure for Immunogold Electron Microscopy: Rapid-Freeze Substitution with Absolute Acetone.

CYTOLOGIA ◽  
1997 ◽  
Vol 62 (3) ◽  
pp. 303-308 ◽  
Author(s):  
Hidenori Takahashi ◽  
Haruko Kuroiwa ◽  
Shin-ya Miyagishima ◽  
Kyoko Toda ◽  
Ryuuichi Itoh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Freeze Substitution ◽  
Immunogold Electron Microscopy

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

scholarly journals Immunolocalization of type III collagen in human articular cartilage prepared by high-pressure cryofixation, freeze-substitution, and low-temperature embedding.

1995 ◽  
Vol 43 (4) ◽  
pp. 421-427 ◽  
Author(s):  
R D Young ◽  
P A Lawrence ◽  
V C Duance ◽  
T Aigner ◽  
P Monaghan
Keyword(s):  
High Pressure ◽  
Articular Cartilage ◽  
Polyclonal Antibodies ◽  
Freeze Substitution ◽  
Immunogold Electron Microscopy ◽  
Type Iii Collagen ◽  
Human Articular Cartilage ◽  
Chemical Fixation ◽  
Osteoarthritic Cartilage ◽  
Type Iii

We localized Type III collagen by immunogold electron microscopy in resin sections of intact normal and osteoarthritic human articular cartilage. Comparisons of antibody staining between tissue prepared by high-pressure cryofixation and freeze-substitution without fixatives and that exposed to conventional mild chemical fixation with paraformaldehyde showed that dedicated cryotechniques yielded superior preservation of epitopes that are modified by chemical fixation, and simultaneously provided good ultrastructural preservation. Type III collagen was detected with two polyclonal antibodies, one against the triple-helical domain of the molecule and a second against the more antigenic, globular amino pro-peptide domain, which in this collagen is retained in the extracellular matrix after secretion. Positive labeling was seen in association with the major interstitial fibrils, suggesting co-polymerization of Types III and II collagen in cartilage. Type III collagen could not be detected in aldehyde-fixed normal cartilage. In fixed osteoarthritic cartilage, Type III was detectable only when the antibody to the amino pro-peptide was employed. In contrast, high-pressure cryofixation and freeze-substitution preserved epitopes for both antibodies, permitting immunodetection of Type III collagen in normal and osteoarthritic cartilage. Cryotechniques offer exciting possibilities for significantly improving the immunolocalization of collagens and other fixative-sensitive antigens in situ.

Immunogold electron microscopy of surface antigens of oral bacteria

1984 ◽  
Vol 30 (8) ◽  
pp. 1008-1013 ◽  
Author(s):  
C. Mouton ◽  
L. Lamonde
Keyword(s):  
Electron Microscopy ◽  
Surface Antigens ◽  
Oral Bacteria ◽  
Immunogold Electron Microscopy ◽  
Bacterial Surface ◽  
Outer Aspect ◽  
Bacteroides Gingivalis ◽  
Cell Envelopes ◽  
Inexpensive Procedure ◽  
Monospecific Antibodies

Colloidal gold particles 3–6 nm in diameter were prepared and stabilized with the IgG fraction of polyspecific rabbit antisera produced against four different oral bacteria. The immunogold markers were used in homologous reactions to label the bacteria in a preembedding procedure for electron microscopy. An indirect immunofluorescence procedure was concurrently used to optimize the labelling conditions before observation with the electron microscope. The immunogold markers labelled fibrillar structures extending outward 50–275 nm from the Gram-positive cell envelopes and a fuzzy 5–10 nm thick capsulelike layer on the outer aspect of Bacteroides gingivalis. The immunogold method appears to be a simple, rapid, and inexpensive procedure suitable for the study of bacterial surface antigens and can be upgraded with the use of monospecific antibodies.

scholarly journals Subcellular Distribution and Relative Expression of Fibrocyte Markers in the CD/1 Mouse Cochlea Assessed by Semiquantitative Immunogold Electron Microscopy

2011 ◽  
Vol 59 (11) ◽  
pp. 984-1000 ◽  
Author(s):  
Shanthini Mahendrasingam ◽  
Catherine Bebb ◽  
Ella Shepard ◽  
David N. Furness
Keyword(s):  
Electron Microscopy ◽  
Tissue Growth ◽  
Immunogold Electron Microscopy ◽  
Spiral Ligament ◽  
Type Ii ◽  
Relative Expression ◽  
Aquaporin 1 ◽  
Cellular Transplantation ◽  
S 100 ◽  
Type V

Spiral ligament fibrocytes function in cochlear homeostasis, maintaining the endocochlear potential by participating in potassium recycling, and fibrocyte degeneration contributes to hearing loss. Their superficial location makes them amenable to replacement by cellular transplantation. Fibrocyte cultures offer one source of transplantable cells, but determining what fibrocyte types they contain and what phenotype transplanted cells may adopt is problematic. Here, we use immunogold electron microscopy to assess the relative expression of markers in native fibrocytes of the CD/1 mouse spiral ligament. Caldesmon and aquaporin 1 are expressed more in type III fibrocytes than any other type. S-100 is strongly expressed in types I, II, and V fibrocytes, and α1Na,K-ATPase is expressed strongly only in types II and V. By combining caldesmon or aquaporin 1 with S-100 and α1Na,K-ATPase, a ratiometric analysis of immunogold density distinguishes all except type II and type V fibrocytes. Other putative markers (creatine kinase BB and connective tissue growth factor) did not provide additional useful analytical attributes. By labeling serial sections or by double or triple labeling with combinations of three antibodies, this technique could be used to distinguish all except type II and type V fibrocytes in culture or after cellular transplantation into the lateral wall.

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