Application of Electron Microscopy to the Study of Photochemical Reactions in Organic Solids

1972 ◽  
Vol 10 (2) ◽  
pp. 573-580 ◽  
Author(s):  
J. M. Thomas
1982 ◽  
Vol 86 (10) ◽  
pp. 1764-1767 ◽  
Author(s):  
J. Swiatkiewicz ◽  
G. Eisenhardt ◽  
P. N. Prasad ◽  
J. M. Thomas ◽  
W. Jones ◽  
...  

1982 ◽  
Vol 85 (4) ◽  
pp. 381-386 ◽  
Author(s):  
T.N. Misra ◽  
Paras N. Prasad

2000 ◽  
Vol 48 (3) ◽  
pp. 433-436 ◽  
Author(s):  
Toshihiro Takizawa ◽  
John M. Robinson

Correlative microscopy is an important approach for bridging the resolution gap between fluorescence and electron microscopy. We have employed FluoroNanogold (FNG) as the detection system in these types of studies. This immunoprobe consists of a gold cluster compound to which a fluorochrome-labeled antibody is covalently linked. In these preparations, the fluorescence signal from FNG is first recorded then the gold cluster compound is subjected to a silver enhancement reaction before examination by electron microscopy. Potential complications are those associated with photochemical reactions that occur during fluorescence microscopy. We have evaluated this and some anti-photobleaching agents (i.e., 1,4-diazabicyclo[2.2.2]octane [DABCO], p-phenylenediamine [PPD], and N-propyl gallate [NPG]) for their utility with FNG in correlative microscopy. When DABCO was employed, the gold signal from FNG was dramatically diminished but the fluorescence signal was unaffected. The gold signal of DABCO-treated samples decreased to approximately 30% of that of the other samples. On the other hand, PPD and NPG did not adversely affect the FNG labeling. We recommend that either PPD or NPG be used and that DABCO be avoided as an antiphotobleaching reagent for this technique.


Author(s):  
S. K. Aggarwal ◽  
P. McAllister ◽  
R. W. Wagner ◽  
B. Rosenberg

Uranyl acetate has been used as an electron stain for en bloc staining as well as for staining ultrathin sections in conjunction with various lead stains (Fig. 1). Present studies reveal that various platinum compounds also show promise as electron stains. Certain platinum compounds have been shown to be effective anti-tumor agents. Of particular interest are the compounds with either uracil or thymine as one of the ligands (cis-Pt(II)-uracil; cis-Pt(II)-thymine). These compounds are amorphous, highly soluble in water and often exhibit an intense blue coloration. These compounds show enough electron density to be used as stains for electron microscopy. Most of the studies are based on various cell lines (human AV, cells, human lymphoma cells, KB cells, Sarcoma-180 ascites cells, chick fibroblasts and HeLa cells) while studies on tissue blocks are in progress.


Author(s):  
Gunter F. Thomas ◽  
M. David Hoggan

In 1968, Sugimura and Yanagawa described a small 25 nm virus like particle in association with the Matsuda strain of infectious canine hepatitis virus (ICHV). Domoto and Yanagawa showed that this particle was dependent on ICHV for its replication in primary dog kidney cell cultures (PDK) and was resistant to heating at 70°C for 10 min, and concluded that it was a canine adeno-associated virus (CAAV). Later studies by Onuma and Yanagawa compared CAAV with the known human serotypes (AAV 1, 2, 3) and AAV-4, known to be associated with African Green Monkeys. Using the complement fixation (CF) test, they found that CAAV was serologically related to AAV-3 and had wide distribution in the dog population of Japan.


Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.


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