In the early 1980s, the decreasing cost of video cameras, tape recorders and other 'consumer electronics' meant that it was possible for cell biologists to incorporate electronic equipment into their daily experiments.
In 1981, Inoué and Allen et al. separately reported the successful pairing of a video camera with a microscope. These two papers revolutionized the field of cell biology, because they made it possible to 'watch' microscopic cellular events for extended periods of time. In addition, it was possible to 'freeze' a frame of the movie, giving the biologist a 'snapshot' of a cellular event, and to enhance the analogue video signal electronically, yielding an image that effectively had a higher contrast than images obtained through the use of a camera.
The Inoué paper included images of a broad range of biological events, and he showed that it was possible to use differential interference contrast (DIC) microscopy to film a sea cucumber spermatozoan extending its acrosomal process. Inoué probed the kinetics of this biological event, during which the acrosomal process can become up to 90 
m long in <10 seconds. Allen et al. described a new method — called Allen video-enhanced contrast (AVEC)–DIC — that they used to examine transport along microtubules in a foraminifer; their images showed that cytoplasmic organelles were able to move along the microtubules in either direction and that they stopped moving if they 'fell off' the microtubule.
An absolutely critical technological advance for the field. This technology allowed investigators to clearly resolve and record movements of organelles and visualize microtubules.
Margaret Titus
These two papers paved the way for further studies that used AVEC–DIC microscopy, for example, in applications ranging from observing fast axonal transport in the giant axon of a squid to monitoring microtubule dynamics in the newt lung epithelium, which conclusively showed that dynamic instability occurred in living cells (see Further reading). In addition, DIC microscopy was instrumental to the discovery of kinesin (see Milestone 15).
