Microphotometry of banded human chromosomes II. Technique for microphotography of banding patterns

As part of a study of chromosome banding patterns by microphotometric measurements of photographic negatives, banded chromosomes were microphotographed in order to evaluate the importance of the size of the condensor (illumination) aperture for obtaining high resolution. The resolution was found to be closely correlated to the numerical aperture of the objective, but within wide limits it was independent of the condensor aperture. The reason is assumed to be light scattering caused by the object, which results in illumination of the full objective aperture. The optimal photographic method was found to include the use of a 63x oil planapochromate objective (NA 1.4) and a total microscope magnification of 250x.