Answer to Question #112020 in Cell Biology for Suresh singh

Question

Difference between Fluorescence microscopy and Phase contrast microscopy

Answer 1

Difference between Fluorescence microscopy and Phase contrast microscopy can be defined by using the following criteria:

- Light source: high pressure mercury vapour ultraviolet lamp in Fluorescence microscopy and typical bright light lamp in Phase contrast microscopy;

- Additional equipment: the set of special UV-filters and objectives in Fluorescence microscopy and the phase-contrast condensor with special objectives in Phase contrast microscopy;

- Specimen preparation: pretrited with fluorochromes dead biological objects or alive objects with autofluorescence properties in Fluorescence microscopy and unstained living or daed organisms/cells in Phase contrast microscopy; 

- Main principle: Fluorescence microscopy is based on the principle of removal of incident illumination by selective absorption, whereas light that has been absorbed by the specimen and re-emitted at an altered wavelength is transmitted. In the Phase contrast microscope, the condenser has an annular diaphragm, which produces a hollow cone of light; the objective has a glass disk (the phase plate) with a thin film of transparent material deposited on it, which accentuates phase changes produced in the specimen. This phase change is observed in the specimen as a difference in light intensity.

- Magnification: this two types of mycroscopy can give the same magnification.