Transmission and Scanning Electron Microscope Facility
Bigelow Laboratory has an electron microscope facility that features (1) a Zeiss 902A transmission electron microscope (TEM) equipped with an EELS system and (2) a Zeiss Supra25 field emission scanning electron microscope (SEM). The TEM is equipped with a goniometer for rotating/tilting sections, the microscope has both digital and film camera systems, and the EELS attachment allows for elemental analysis, removal of inelastic electrons for better resolution and the examination of semi-thick sections (up to 600 nm). The goniometer and the thick section capabilities are excellent tools for producing stereo pair images from moderately thick cell slices, and these can be used reconstructing three-dimensional models of cells. The TEM is supported with two ultramicrotomes, a new RMC PT-X and an older Reichert Ultracut E. Individual scientists are expected to purchase their own diamond knives for cutting thin sections. The field emission SEM provides ultrahigh quality images, and it is equipped with a STEM, energy dispersive X-ray spectrophotometer (EDS) and Robinson diffraction attachments. The STEM (scanning transmission electron microscopy) produces SEM images at the same time as transmitted electron images when viewing certain electron transparent materials (e.g., cells on a grid). EDS is used to examine element composition, especially of biological materials. The Robinson diffraction gives element composition, especially for metal objects. The EM suite has a Denton Vacuum floor-model vacuum evaporator (model DV-502A) and a Denton Vacuum desk-model sputter-coater/evaporator (Desk IV, with Carbon Accessory). These two instruments coat grids and SEM specimens with carbon or a variety of metals (e.g., gold, platinium, tungsten). The facility also has a LKB glass knifemaker, a Zeiss SV8 dissecting microscope equipped with ring illumination for examining stubs and grids, a Metler scale, a pH meter, embedding oven, refrigerator with freezer, vacuum pump, and so forth.
The CCMP uses the instruments to identify algal culture strains (quality control) and Bigelow scientists use the EM facility in their research. For example, Andersen, Emerson, Fields, and Wilson are studying algal ultrastructure, iron-oxidizing bacteria, copepod sensory organelles, and marine viruses, respectively.
The EM facility is currently supervised by Dr. Robert Andersen, and inquiries for use should be directed to him. The goal of the facility is to train users so that they can operate the electron microscopes and support equipment without supervision. Once trained, users sign up for time blocks and carry out their studies unsupervised. All users should be approved by Andersen, i.e., trained users should not train their technicians or other scientists without first discussing the matter with Andersen. The TEM has a $35 per beam hour charge, and this money is used to support any instrument repairs. The SEM is currently free, but eventually it will also have an hourly fee. Users are expected to provide their own supplies (e.g., grids, stubs, stains).