A Method for Electron Microscopic Study of Tissue Culture Cell Monolayers Grown in Tubes

Author(s):  
R. Stephens ◽  
G. Schidlovsky ◽  
S. Kuzmic ◽  
P. Gaudreau

The usual method of scraping or trypsinization to detach tissue culture cell sheets from their glass substrate for further pelletization and processing for electron microscopy introduces objectionable morphological alterations. It is also impossible under these conditions to study a particular area or individual cell which have been preselected by light microscopy in the living state.Several schemes which obviate centrifugation and allow the embedding of nondetached tissue culture cells have been proposed. However, they all preserve only a small part of the cell sheet and make use of inverted gelatin capsules which are in this case difficult to handle.We have evolved and used over a period of several years a technique which allows the embedding of a complete cell sheet growing at the inner surface of a tissue culture roller tube. Observation of the same cell by light microscopy in the living and embedded states followed by electron microscopy is performed conveniently.

1994 ◽  
Vol 127 (6) ◽  
pp. 1527-1536 ◽  
Author(s):  
M Pruschy ◽  
Y Ju ◽  
L Spitz ◽  
E Carafoli ◽  
D S Goldfarb

Calmodulin (CaM) potentiates Ca(2+)-dependent signaling pathways in both the cytoplasm and nucleus. We have investigated the mechanism of CaM nuclear transport using tissue culture cell microinjection and a permeabilized cell import assay. The inhibition of CaM import by the translocation inhibitor wheat germ agglutinin (WGA) and by chilling, indicates that CaM import is facilitated, but because ATP depletion does not affect CaM import, the mechanism does not appear to be active. Chilling and WGA arrest persist in ATP-depleted cells, indicating that CaM is not retained in the cytoplasm by an ATP-dependent mechanism. In permeabilized cells, both Ca(2+)-CaM and Ca(2+)-free CaM are sensitive to extract-dependent WGA and chilling import inhibition. Titration experiments in microinjected and permeabilized cells indicate that a saturable cytosolic factor(s) mediates chilling and WGA arrest.


1979 ◽  
Vol 182 (1) ◽  
pp. 157-164 ◽  
Author(s):  
J M Graham ◽  
J K Sandall

1. The disruption of various types of tissue-culture cells by (a) incubation in solutions of 1.2 M-glycerol and (b) transfer of the glycerol-loaded cells to relatively hypo-osmotic solutions of 0.25 M-sucrose was studied. 2. Bivalent cations (2mM-Mg2+) were generally included to preserve the nuclei, but some cells (polyoma-virus-transformed baby-hamster kidney cells) failed to be disrupted adequately under these conditions. 3. Other cells (mouse-embryo fibroblasts) required additional gentle Dounce homogenization to effect complete cell breakage. 4. Purification of the whole homogenate was carried out by a combination of differential centrifugation and sedimentation or flotation through sucrose gradients. 5. Enzyme analysis showed that plasma-membrane, endoplasmic-reticulum and mitochondrial fractions were obtained in good yield and purity.


2008 ◽  
Vol 52 (6) ◽  
pp. 2190-2195 ◽  
Author(s):  
Paul L. Hinkson ◽  
Carol Dinardo ◽  
Daniel DeCiero ◽  
Jeffrey D. Klinger ◽  
Robert H. Barker

ABSTRACTClostridium difficile-associated diarrhea (CDAD) is caused by the toxins the organism produces when it overgrows in the colon as a consequence of antibiotic depletion of normal flora. Conventional antibiotic treatment of CDAD increases the likelihood of recurrent disease by again suppressing normal bacterial flora. Tolevamer, a novel toxin-binding polymer, was developed to ameliorate the disease without adversely affecting normal flora. In the current study, tolevamer was tested for its ability to neutralize clostridial toxins produced by the epidemic BI/027 strains, thereby preventing toxin-mediated tissue culture cell rounding. The titers of toxin-containingC. difficileculture supernatants were determined using confluent cell monolayers, and then the supernatants were used in assays containing dilutions of tolevamer to determine the lowest concentration of tolevamer that prevented ≥90% cytotoxicity. Tolevamer neutralized toxins in the supernatants of allC. difficilestrains tested. Specific antibodies against the large clostridial toxins TcdA and TcdB also neutralized the cytopathic effect, suggesting that tolevamer is specifically neutralizing these toxins and that the binary toxin (whose genes are carried by the BI/027 strains) is not a significant source of cytopathology against tissue culture cells in vitro.


Author(s):  
Joseph E. Mazurkiewicz

Immunocytochemistry is a powerful investigative approach in which one of the most exacting examples of specificity, that of the reaction of an antibody with its antigen, isused to localize tissue and cell specific molecules in situ. Following the introduction of fluorescent labeled antibodies in T950, a large number of molecules of biological interest had been studied with light microscopy, especially antigens involved in the pathogenesis of some diseases. However, with advances in electron microscopy, newer methods were needed which could reveal these reactions at the ultrastructural level. An electron dense label that could be coupled to an antibody without the loss of immunologic activity was desired.


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