MICRB 201 Lecture Notes - Lecture 3: Gram-Positive Bacteria, General Idea, Globus Pallidus
13 Sep 2017
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Microscopes produce an enlarges image of object, i. e. magnification: length of smallest object seen by human eye ~ 0. 2 mm (fig 2. 7) Two broad classes of microscopes: simple: single lens, compound: more than one lens, mag. Power is related to the focal length (f) of a lens: Small f (fat lens) = high mag. Long f (thin lens) = low mag. Strength of a microscope is known as its magnifying power. Common types of microscopes: light microscopes: uses light to produce image, electron microscopes: uses electrons to produce image. Lambda is the wavelength of light used to illuminate object. Na is the numerical aperture of the lens (indication of the light-gathering ability of lens; fig. Thus, the smaller the value of d (slide 4: the better the resolution, the closer the objects that can be resolved. Decrease lambda (blue @ 450nm, better than green light @ 550nm; slide 4)
