This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. For this reporting period (6/1/08-5/31/09). The microscope was used extensively (approx. 20 regular users). We acquired a total of 269 tilt-series (88 cryo and 182 room temperature). We had very little service work (~16 days) done on the microscope. The microscope was heavily used during the typical workday (8-6 M-F) with 82% of our work done during those hours. In addition, the microscope was used 285 of the 360 available days last year with an average of 38.5 hours/week (2006 hours/52 weeks). The F20 was used 48% for cryo-imaging, 24% room temperature imaging, 9% for cryo-tomography, 7% for service, 5% for training, and 1% for development.