Landmarks in biological light microscopy

Abstract

SUMMARYThe pioneering seventeenth‐century work of Hooke (using the compound microscope) and Leeuwenhoek (using the simple microscope) was followed in the eighteenth century by a period of comparative stagnation until the early nineteenth‐century work of Lister (who evolved the principle of aplanatic focal points in lens design). The founding of the Microscopical Society of London in 1839 reflected the increasing importance of the microscope as a scientific instrument and its involvement in specimen preparation techniques, cell theory and bacteriology is described.The pursuit of increased resolving power—in particular the development of apochromatic lenses by Abbe and Zeiss and enhanced contrast techniques—polarized fight, u.v. microscopy, u.v. absorption and fluorescence, phase contrast and the differential interference contrast techniques, etc., are discussed. The story of microscopy in the twentieth century is one of interlocking discoveries and advances and the techniques of epi‐illumination in scanning fluorescence microscopy, video acquisition and analyses of images in digital form and confocal scanning microscopy are surveyed. It is concluded that these techniques have opened up whole new areas for the future development of light microscopy.