A Freeze-Fracture & Etching System for Northwestern Univ

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The requested funds will be used to purchase a Freeze-Fracture and Etching System that will be the cornerstone instrument of a new Cryopreparation Facility to be housed in the Electron Probe Instrumentation Center at Northwestern University. We currently have an old freeze-fracture and etching system, but it is limited to a small user base, has limited capacity to process samples, is limited in resolution, is subject to breakdown, and is generally difficult to use. This has limited the potential for studies involving cryopreparation at Northwestern University. The new device has a much greater capability to process samples, is much easier to use and thus will facilitate a much larger user base, and should be less prone to breakdown. The device to be purchased is a Cressington CFE Freeze- Fracture Replication System outfitted with low and 45 degree angle platinum/carbon and tantalum/tungsten shadowing sources, two 90 degree carbon backing evaporation guns, two microtome holders, two Heuser mount specimen stages, one gold hat specimen stage, one double replica stage, two quad Heuser mount stages, low and high angle quartz crystal thickness monitors, dewar pumping and shield kit for ultra-low temperature coating. This system will allow freeze- fracture and freeze-etching of specimens, coating with both platinum/carbon and tantalum/tungsten at low and high angles, high throughput (4 times higher than current device and up to 50 runs or 200 specimens without venting) and coating at ultralow temperature to achieve nearly "grainless" PLATINUM/CARBON COVERAGE. In combination with the different methods of freeaing that will be available (a Med-Vac helium slam freezer and a Leica CPC Universal cryoworkstation), this will provide a versatile facility for cryopreparation. This equipment will be used in a variety of studies including examination of the changes in extracellular matrix architecture in glaucoma, age-related macular degeneration, and lymphangiogenesis, characterization of a variety of biomimetic/bioinspired biomaterials, ultrastructural examination of the intracellular matrix of vascular endothelial cells, characterization of synaptic junctions, detailed examination of the interaction of biomimetic polymeric scaffolds with ovarian follicles and ovarian somatic cells with oocyte, determining the polymorphic phase of cationic and anionic mixtures, investigating the morphology of fused lipid bilayer vesicles, and analyzing the supramolecular organization of the actin machinery in the motility of crawling cells.