Inverted biological microscope
The inverted biological microscope was developed for observations of living cells (cultured cells). Cells targeted for observation are cultured in a Carrel flask or Petri dish. Therefore, the use of conventional upright microscopes presents a number of problems, such as the objective lens dipping into the culture fluid, limitations on the specimen vessel used, difficulties in adjusting the phase contrast, and the image getting out of focus when observed over long time periods. The inverted biological microscope (tissue culture microscope) was developed to resolve such problems. The basic optical system used technology already developed for inverted metallurgical microscopes. Olympus launched the PMB in 1958 and the simplified CK in 1966. Thereafter, Olympus used UIS optics to develop the IX Series, which is still in use today.