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Unformatted text preview: calculate the limit of resolution of this microscope. d = (0.61) x (450 nm) / 1.4 = approx 190 200 nm (so, two objects closer together than 200 nm would appear as one) d. The set up described above provides a certain magnification and resolution, but what about contrast ( visibility)? Describe two different technical approaches that can be used with the light microscope to improve specimen contrast . (1 ) Alter the specimen by treating it with selective stains or vital dyes that will bind to and highlight specific organelles and cell components. Increase in contrast increases visibility. (2) Alter the optics of the light microscope. Use phase- contrast or differential interference contrast (DIC) microscope to convert diffracted light passing through the specimen to light vs dark contrast. This may provide good contrast (visibility) in living specimens without adding dyes. Demo...
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- Spring '08