The Structural Electron Microscopy Facility at BUSM
Electron Cryo-Microscopy and 3D Image Reconstruction
We redesigned our EM suite to house a Tecnai F20 microscope, that allows us to image frozen biological specimens at ~5-10Å.
The Tecnai F20 complements our cryo-CM12, which is equipped with low dose kit, 2 Gatan cold holders, computerized Specimen Relocation System (SRS) and Dr. I. Tews dynamic defocus spot scan package (see image above). The CM12 is currently in a dry room environment that minimizes contamination problems with frozen specimens. The microscopes are situated in adjacent rooms located on the first floor (on bedrock) of the 17 year old Center for Advanced Medical Research building.
The newly renovated microscope suite is comprised of 7 rooms, including two microscope rooms, adjoining darkroom and inner prep room that are climate-controlled with a Harris dry-room conditioning system. The inner prep room contains a custom built plunge freezing device (see image above). Two additional custom plunge freezers are located in a cold room. The EM suite also houses an outer prep room with Gatan pumping station, dual glow discharge unit and carbon shadower, equipped with a stage for rotary metal shadowing. A computing room will also be housed within the EM suite. Finally, a custom-built vertical optical diffractometer and Eikonics scanner are located within a separate room on the same floor as the microscopes. We plan in the near future to purchase a Zeiss SCAI scanner, but currently have access to a SCAI purchased by Dr. T. Rapoport with HHMI support and located at Harvard Medical School in the EM group of Dr. T. Walz. Day to day operations of the EM facility are overseen by D. Gantz, who has over 20 years of experience in microscopy. He also runs a separate histology laboratory on the 3rd floor that houses ultra microtomes for both plastic and frozen sections.
Computing Facilities for the Structural EM Group
The EM Structural group has an extensive array of computers that are networked within the Department of Physiology and Biophysics with internet access maintained by BUSM. The user group currently has numerous SGIs (an octane with dual processors, an O2 and 4 Indigo workstations). In addition, two 450Mhz alpha workstations are currently used (1 under DEC Unix and 1 under VMS). The group also carries out large scale single particle processing jobs on an 8 processor (250Mhz/processor) SGI Origin server with 1.4 Terrabytes of diskspace. In addition, we have access to the BU Super Computing Facility (~192 processors in two SGI machines). Finally, the Akey and Bullitt laboratories each have PCs with scanners and color printers for graphics work.
The Greater Boston Area Structural EM Community
The Structural EM groups at Boston University School of Medicine (comprised of Drs. C. Akey, E. Bullitt and W. Lehman) are part of a larger group within the greater Boston area that contains 7 laboratories (see below).
This concentration of structural EM groups in the greater Boston area is unprecedented. This consortium is now planning to hold a yearly meeting, to host seminars from members of the group. Obviously, this geographical centralization of laboratories with different and overlapping expertise provides a rich environment for carrying out structural EM studies. Indeed, there are currently 2 FEG microscopes in the Boston area. Moreover, the Brandeis groups are in the process of setting up a facility with a 300kv FEG microscope and liquid helium cold stage, which will be made available to other groups. Hence, we anticipate having all the facilities in Boston needed to carry our high resolution biological EM. Finally, a perspective post-doctoral fellow could easily plan consecutive post-doctoral stints at different laboratories within the Boston area thereby minimizing disruptions to family and personal lives.