125. Delgado III, R. M., Fink, M. J., and
R. M. Brown, Jr. 1989. Imaging of submicron objects with the light
microscope. Proc. Royal Mic. Soc. London. 154(2):129-141.
Using conventional optics coupled with image
processing, several submicron objects have been studied with light
microscopy. These include polystyrene beads (88, 264 and 557nm),
frustules from the diatom Pleurosigma angulatum and the
T-4 bacteriophage, either attached to its host, Escherichia
coli, or free in the medium. The best results were obtained
from dark-field and phase contrast optics. Digital image processing
with the use of color look-up tables in real time greatly promoted
precise focusing of the objects. Selective discrimination of
image histogram gray values allowed for selection of a sharp contour
boundary, thus more effectively delimiting the submicron objects.
User interactive scaling of the diffraction limited boundaries
greatly improved discrimination of the objects. While Abbe limits
have not been surpassed by these techniques, the greater 'apparent
resolution' could be attributable to a 'better recognition' of
the submicron objects examined. Equivalence of images of polystyrene
beads and bacteriophages was demonstrated with light and electron
microscopy of the same field.