Analytical and Technical Services
Microscopy
Reserve time on the Microscopes with FACES
Contact Deb Driscoll — debdris@esf.edu — to obtain log-on information for the FACES scheduling system.
Scanning Electron Microscope
The JEOL JSM-IT100 is capable of 33-300,000X magnification with 4nm resolution. It is equipped with a secondary electron detector, backscatter electron detector, low vacuum secondary detector and silicon drift x-ray detector. The thermionic electron gun can be set from 1-20kV. The SEM scans a beam of electrons over the specimen to produce a magnified image. The electrons from the beam hit the surface of the sample and bounce off it. The chosen detector registers these scattered electrons and turns them into a picture. The x-ray detector and software enable the collection and manipulation of energy dispersive x-ray spectra as well as element maps and point and line analyses. Samples must be conductive to prevent the buildup of charge and repulsion of the electron beam. If not conductive, samples can be made conductive with our Edwards sputter and carbon coater. We also have available a Tousimis critical point dryer for samples in ethanol.
The SEM can handle a large variety of samples under a large variety of conditions. An insulated cryo-stub is available for in-situ examination/freeze drying of biological samples and a STEM holder for thin samples on grids. The stage has both tilt and rotation features. We offer group demos and classes as well as individualized training* in operation of the scope.
Samples imaged with the SEM have ranged from large to microscopic and biological to man-made: insects, pollen buckets, nanoparticles, many types of metals, polymer composites, and Metal-organic frameworks (MOFs), to name just a few.
Sample Submission
Email debdris@esf.edu to discuss SEM projects/samples.
Charges are as follows:
Internal (ESF) Users: $25 per hour
Academic Customers: $65 per hour with ATS assistance or training / $40 per hour for
independent users
Private Sector Customers: $100 per hour
Sputter Coating: $20 per run
*Training provided at the assisted rate. Once trained, rate will change to independent
rate.
Transmission Electron Microscope
Our transmission electron microscope is a JEOL JSM-2000EX. The JSM 2000EX has an accelerating voltage of 80-200 kV. This instrument has a lattice image resolution of 0.14nm and a point image resolution of 0.28 nm and can be operated at a magnification of 1,000,000 X. The variable accelerating voltage permits the observation of negative stained proteins, bacteria, viruses or ultrathin sections at the lower kV as well as superior resolution of nanoparticles and thick specimens at higher voltages. It has a side entry tilt stage goniometer that can perform 3D reconstruction of macromolecules, single particles and tomography of whole cells. It can also perform micro electron diffraction yielding atomic resolution on thin samples as has been accomplished with purple membrane. Other capabilities are a specimen position memory function, an auto through focus function, an optimum underfocus function, a minimum dose system, and an image data recording function. The lab has ancillary equipment that allows for ultrathin (60nm) sectioning using diamond knives of resin or frozen material, freeze-substitution, rotary shadowing, immunolabeling, freeze fracturing of various samples both biological and materials.
Light Microscopes and Image Analysis
The Center is outfitted with an array of Zeiss and Nikon light microscopes that are equipped for various LM techniques. These techniques include brightfield (transmitted and reflected), phase contrast, darkfield, UV fluorescence using multiple filters, video enhanced contrast, polarization, oil immersion, and Nomarski differential interference contrast. Images are recorded using a Spot RT or K digital cameras (1600x1200 pixels) and recorded into Spot, Image Pro Plus 7.0, Image J or Photoshop. The lab is set up for correlative microscopy where the same sample is viewed by light, scanning and transmission electron microscopy. The lab has several sliding microtomes for preparing thin sections of wood or hardened materials for light microscopy.