Optical microscopy utilizes a lens – or lenses – to image objects at greater magnification than the human eye can perceive. The most rudimentary microscopes consisting of just one lens – essentially a magnifying glass – appeared over five hundred years ago. With the addition of more lenses, compound microscopes were created and the complexity of optical microscopes increased from there.
Today’s light microscopes range in capability from simple classroom microscopes to incredibly complex research microscopes which utilize an array of features to improve their performance. Common features include digital cameras, automated stages, specialized sample holders, and micromanipulators. Optical microscopes now come in several different variations, depending on the application. These include fluorescence, stereo, laser scanning, and confocal microscopes. Optical microscopes began as rudimentary tools for the primitive scientist but have developed into powerful, versatile research instruments.
The resolution of optical microscopes has traditionally been limited by the diffraction limit. The diffraction limit is related to the wavelength of light and represents the point beyond which an optical microscope can effectively resolve features. New developments have allowed optical microscopes to push beyond this limit, including scanning near-field optical microscopy and the use of fluorescence.
As optical microscopes push to higher and higher resolutions, their need for environmental isolation has increased. Many confocal and fluorescence microscopes are sold with standard vibration isolation systems. Typically, air-based systems are sufficient, but active vibration control may be required when using these instruments in a noisy environment.
Optical microscopes are often employed in bioengineering applications. These applications often require the manipulation of cells using micropipettes, injectors, and micromanipulators. These tools, because they are long and thin, are particularly vulnerable to noise and vibration issues. They also require a fine degree of control, which is impossible without proper vibration control. Neglecting to compensate for environmental noise can lead to costly mistakes.
Biological applications are often sensitive to temperature variation, as it can cause cells to behave differently or even to die. Care should be taken when selecting a lab space to ensure that there are not wide fluctuations in temperature throughout the day. It should also be noted that some biological applications are sensitive to light, in which case a light shield should be employed or integrated into a soundproof hood.