0 60 m x 11 15 m 100 times below the limit of the

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Unformatted text preview: crobe E. coli-> 2.0-6.0 µm X 1.1-1.5 µm ~100 times below the limit of the naked eye. Light Microscope • Magnification: COMPOUND MICROSCOPE, LENS PLUS LENS (MORE THAN ONE LENS) SIMPLE: ONE LENS Simple (10X) Compound (10X x 10X = 100X) YOU CAN MAGNIFY HUNDREDS OF TIMES, BUT YOU LOSE RESOLUTION. AIR TO GLASS RESULTS IN REFRACTION. • Contrast: Stain (Brightfield: Neg/Pos/Differential) 2 Optical (Phase contrast, darkfield, etc) 1 EMPTY MAG: INCREASE IN MAG WITH NO INC IN RESOLUTION OPTICAL CONTRAST: LIGHT PASSES THRU SPECIMEN • Resolution: RP = / NA x 2 IS BENT, TAKE ADVANTAGE BY SUBTRACTING BENT LIGHT NA = numerical aperture FROM LIGHT PASSING THRU MEDIA, RESULTS IN OPTICAL METHOD TO ACHIEVE CONTRAST. RP = resolving power NA = n sin n = refractive index (theta) = property of lens -->RP = 550 nm / (1.3) x (2) = 211 nm NUMERICAL APERATURE: REFERS TO QUALITY OF LENS, LENS OF MICROSCOPE APPROACHES SPECIMEN, CLOSE TO LENS, = HIGHER MAG (LENS MUST BE IN FOCUS) TAKE ANGLE OF CONE OF LIGHT THAT ACCEPTS BY LENS IN FOCUS, THE ANGLE IS TH...
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