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Electron microscopy is an indispensible tool in the world of life scientists. Cell biologists use electron microscopy to visualize tissues and cells. Pathologists use them to better understand the molecular mechanisms of disease. Virologists observe individual viruses and virus-like particles. The technique is required for the design and testing of novel biomaterials, as well as in drug discovery and delivery.
These samples types are normally a major challenge to image with a transmission electron microscope due to the inherent low contrast provided by their molecular composition. A low voltage electron microscope, the LVEM5 can completely eliminate these contract issues.
Low-energy electrons interact much more strongly with the sample than the high-energy electrons from classical transmission electron microscopes (TEM). Electrons in the LVEM5 are strongly scattered by organic materials resulting in strong differentiation of features. The density difference required in a sample to give a 5% contrast difference at 5 kV is only 0.074 g/cm3.
The low accelerating voltage allows for high contrast results without the addition of contrast-enhancing staining procedures.
The LVEM5 electron microscope assists researchers by providing high resolution and rapid imaging of their samples. The LVEM5 shifts the cost-benefit balance by providing nanometer level resolution across three imaging modes: TEM, scanning electron microscopy, and scanning transmission electron microscopy. The LVEM5 system combines all these functionality in a tabletop electron microscope, and helps keep time-to-results and efforts-to-results at minimal levels.
The electron source determines in large measure the parameters of an electron microscope. The Schottky type field emission gun employed by the LVEM5 has very high brightness and spatial coherency.
Digital imaging is by means of a Peltier-cooled CCD camera mounted on the top of the LVEM5. The camera is optimized for low-light, high dynamic range image capture. The magnified image from the light optics is captured for subsequent viewing and analysis.
A backscattered electron detector has been directly incorporated into an electron optics column that was originally designed for transmission electron microscopy alone, enabling scanning electron microscopy to be performed in parallel.
The LVEM5 is designed to operate without any cooling. With conventional electron microscopes active cooling is required to remove considerable heat generated by electric current circulating in the electromagnetic lenses. The permanent magnet lenses used in the LVEM5 remove any need for cooling of its components.
Ion pumps are inherently dry, vibration-free, and achieve very high vacuum levels. They use no oil as do mechanical rotary-pumps and diffusion pumps. By making use of specially designed ion getter pumps, the LVEM5 avoids contamination in the sample space, resulting in stable imaging conditions and absence of artifacts.
The operating console allows the operator to operate the system and observe results via the monitor, away from the microscope body. Feedback is provided directly on the control panel, as well as through the LVEM5’s comprehensive software.
Filed Under: Drug Discovery
