The microscope has long been the telescope’s poor cousin. Both tools were invented at almost the same time (around 1600). The telescope had urgent applications (spotting land and ships); was more easily perfected (optically); and was soon revealing the cosmos’ secrets. The microscope enlarged things already in hand but severely distorted them. For two centuries, the microscope was more of a novelty item than a practical instrument.
Now the microscope is poised to illuminate normal and abnormal life processes like never before.
Sure, the microscope has been used for biology research since the days of Robert Hooke and Antony Leeuwenhoek. However, it wasn’t very reliable until Joseph Jackson Lister (father of the famous Joseph Lister) developed a formula for minimizing spherical and chromatic aberration—eliminating dependence on trial and error techniques. Within about a century the wavelength of visible light became the limiting factor for achieving greater resolution.
Scientists developed ultraviolet and electron microscopes to get around the wavelength limitations of visible light. But humans can’t see UV light, so it was used to produce fluorescence (which could be seen) or images on photographic film. The electron microscope, which also relied on film for many years, had the further disadvantage that special specimen preparation was required.
There have been two big changes recently. The marriage of the microscope and digital camera (with real-time display) now permits one instrument to span infrared to visible light to ultraviolet. And electron microscope makers such as FEI Company are exploiting vitrification to avoid the water crystallization that has traditionally plagued the freezing of biological specimens.
Combine vitrification and 3D/4D digital image processing and you have the prospect of, for example, observing intricate cellular processes first hand and even automating genome sequencing. The electron microscope becomes something analogous to a CT scanner—except this scanner can see down to individual atoms. The possibilities downstream are mind boggling.
