Laboratory Microscopes

Applications of laboratory microscopes

The goal of any laboratory microscope is to produce clear, high-quality images, whether an optical microscope, which uses light to generate the image, a scanning or transmission electron microscope (using electrons), or a scanning probe microscope (using a probe). Upright microscopes are the most common type, with the lighting system below the stage and the lens system above; inverted microscopes, particularly useful for cell culture, reverse this configuration. Applications include biotechnology, pharmaceutical research, nanophysics, microelectronics, and geology.

Commonly used compound microscopes are usually binocular (two eyepieces) and use multiple lenses to produce a 2-D image. They can achieve a maximum of about 1500X magnification and are popular for use in biology and in forensic labs. Stereo microscopes offer 3-D viewing at lower magnification and are available in fixed and zoom variations. Digital microscopes eliminate eyepieces, combining optics with a CCD camera to view images on a computer screen.

Techniques range from simple brightfield to darkfield, phase contrast, differential interference contrast, confocal (useful for thick specimens), and fluorescence microscopy, which continues to prove its value in areas such as cell biology, genetics, and embryology. The use of polarized light in polarizing microscopes results in increased image contrast.

Inverted Fluorescence Microscope

How do I choose a laboratory microscope?

The basic components of an optical microscope consist of optics, a stage to support the specimen, and a source of light; however, these features can be very simple to highly complex, depending on your needs and budget. A state-of-the-art design can feature multiple illuminators, polarizers, DIC and phase contrast options, fluorescence attachments, automatic exposure control, and zoom capabilities.

Since the objectives determine the image quality that the microscope can produce, it makes sense to start with one that will eliminate most optical aberrations. Types include plan achromat, semi-apochromat, and apochromat, as well as water and oil objectives.

Depending on your application, additional features to look for may include high numeric apertures, long working distances, objectives that permit multimode imaging, digital and advanced motorization capabilities, and updated illumination systems.