An Automated DNA Sequencer for Studies of Phylogeny, Population Structure, Coevolution, and Development

点击翻译按钮获取中文摘要

The proposal is for the acquisition of a Field-Emission Gun Scanning Electron Microscope (FEG-SEM) and associated X-ray microanalysis system. Field emission electron sources are very stable even at low accelerating voltages (1 KeV) and their usage in a SEM greatly enhances the capabilities of a FEG-SEM when compared with instruments that use a thermionic emitter electron source. The most significant advantage of a FEG-SEM is its ability to image specimens that are below the limits of resolution of a conventional SEM. A FEG-SEM can have a resolution that is 1 to 1.5 orders of magnitude greater than a comparable conventional SEM. The fact that a FEG-SEM can operate at low accelerating voltages means that one is often able to examine samples that do not require much additional conductive coating. Despite the large number of researchers at the University of Georgia who routinely use scanning electron microscopy, a SEM of suitable quality for high resolution/low KeV work is presently not available anywhere on campus. The ability to create SEM images of microscopic specimens is of critical importance to a wide variety of researchers at the University of Georgia. This is especially important when one is working at very high magnifications where the coating itself may be what is visualized and not the object of study. As configured, this FEG-SEM would also enable researchers to conduct elemental analyses using EDS X-ray at a much higher level of precision than is possible with the Center's present instrument. A final advantage that a FEGSEM has over the Center's present SEM is the ability to capture the images digitally in a high resolution format that can then be further processed or analyzed either on the Center's imaging computers or on any computer linked to the Ethernet. The Center for Ultrastructural Research is the central facility that provides University of Georgia researchers a variety of specialized equipment and expertise in the area of electron and light mic roscopy. For the past five years the Center has assisted with an average of 60 different research laboratories representing 25 different departments or academic units per year. The Center also teaches formal courses (Scanning Electron Microscopy, Transmission Electron Microscopy, Techniques in Modern Microscopy) to both graduate and undergraduates students. The addition of a FEG-SEM to the Center would greatly enhance the research capabilities of those working with both biological and non-biological specimens and is seen as a critical acquisition in ensuring that researchers and students have access to state of the art imaging instruments.