Immunocytochemical Detection Systems

Author(s):  
Lars-Inge Larsson
Author(s):  
A. V. Crewe

If the resolving power of a scanning electron microscope can be improved until it is comparable to that of a conventional microscope, it would serve as a valuable additional tool in many investigations.The salient feature of scanning microscopes is that the image-forming process takes place before the electrons strike the specimen. This means that several different detection systems can be employed in order to present information about the specimen. In our own particular work we have concentrated on the use of energy loss information in the beam which is transmitted through the specimen, but there are also numerous other possibilities (such as secondary emission, generation of X-rays, and cathode luminescence).Another difference between the pictures one would obtain from the scanning microscope and those obtained from a conventional microscope is that the diffraction phenomena are totally different. The only diffraction phenomena which would be seen in the scanning microscope are those which exist in the beam itself, and not those produced by the specimen.


Author(s):  
Kuixiong Gao ◽  
Randal E. Morris ◽  
Bruce F. Giffin ◽  
Robert R. Cardell

Several enzymes are involved in the regulation of anabolic and catabolic pathways of carbohydrate metabolism in liver parenchymal cells. The lobular distribution of glycogen synthase (GS), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen phosphorylase (GP) was studied by immunocytochemistry using cryosections of normal fed and fasted rat liver. Since sections of tissue embedded in polyethylene glycol (PEG) show good morphological preservation and increased detectability for immunocytochemical localization of antigenic sites, and semithin sections of Visio-Bond (VB) embedded tissue provide higher resolution of cellular structure, we applied these techniques and immunogold-silver stain (IGSS) for a more accurate localization of hepatic carbohydrate metabolic enzymes.


Author(s):  
G.D. Danilatos

The environmental scanning electron microscope (ESEM) has evolved as the natural extension of the scanning electron microscope (SEM), both historically and technologically. ESEM allows the introduction of a gaseous environment in the specimen chamber, whereas SEM operates in vacuum. One of the detection systems in ESEM, namely, the gaseous detection device (GDD) is based on the presence of gas as a detection medium. This might be interpreted as a necessary condition for the ESEM to remain operational and, hence, one might have to change instruments for operation at low or high vacuum. Initially, we may maintain the presence of a conventional secondary electron (E-T) detector in a "stand-by" position to switch on when the vacuum becomes satisfactory for its operation. However, the "rough" or "low vacuum" range of pressure may still be considered as inaccessible by both the GDD and the E-T detector, because the former has presumably very small gain and the latter still breaks down.


Acta Naturae ◽  
2015 ◽  
Vol 7 (2) ◽  
pp. 42-47 ◽  
Author(s):  
V. V. Gusel’nikova ◽  
D. E. Korzhevskiy

The NeuN protein is localized in nuclei and perinuclear cytoplasm of most of the neurons in the central nervous system of mammals. Monoclonal antibodies to the NeuN protein have been actively used in the immunohistochemical research of neuronal differentiation to assess the functional state of neurons in norm and pathology for more than 20 years. Recently, NeuN antibodies have begun to be applied in the differential morphological diagnosis of cancer. However, the structure of the protein, which can be revealed by antibodies to NeuN, remained unknown until recently, and the functions of the protein are still not fully clear. In the present mini-review, data on NeuN accumulated so far are summarized and analyzed. Data on the structure and properties of the protein, its isoforms, intracellular localization, and hypothesized functions are reported. The application field of immunocytochemical detection of NeuN in scientific and clinical studies, as well as the difficulties in the interpretation of the obtained experimental data and their possible causes, is described in details.


2003 ◽  
Vol 773 ◽  
Author(s):  
Myung-Il Park ◽  
Jonging Hong ◽  
Dae Sung Yoon ◽  
Chong-Ook Park ◽  
Geunbae Im

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.


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