Dark Field Microscopy

Dark-field - (visible light 500 mm). Produces a bright image of the object against a dark background. Used to observe living, b unstained preparations Best for observing Pale objects. Specimen appear light against dark background. Increases contrast and enables observation of more detail. Good for watching bacterial motion eye Outlanten Speciman objection lers only right slephand lers. is Unreflected light Condencer lers - opaque disc II light

Modified londenser contains disc. in center. Only light refracted by specimen can enter the objective Objects surrounded by halo Advantage Can see smaller objects like spirocheta internal structures highlighted. Disadvantage Object look bigger than they actually are. When filter is used the entire light will not fall so only some areas are light background dark. filter/ The sample is analysed Intact in Dark field opaque dis, gaponly allows eye light eye place facular eye filter only called eye-piece Anular ning objective lens(10x, 40x, 100x) O. ens sample stage stage condition wonderser (11/17 (Diathrogm) filter lopaque DBL (Anwaring) Bright -field Dark-field