Three-dimensional information is important for studying cellular organization and function, and many approaches have been used over the years to reconstruct the three-dimensional structure of microscopic objects (Gaunt and Gaunt, 1978; Inoué, 1986). However, most of them are limited to the analysis of static objects. We have developed a simple and inexpensive method of obtaining three-dimensional information on dynamic processes in living cells. This method, which we have named ‘double-focal videomicroscopy’, yields images at two different focal planes simultaneously, making it possible to obtain information along the axis of observation. This method is especially useful for studying rapid cell movement, such as sperm motility.
Although the focus control is usually used when looking at different focal planes, such images may also be brought into focus by changing the mechanical tube length of the microscope. This principle is applied in the case of double-focal microscopy. By using the...
