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“illumination” Light (visible) Fluorescent U-V Electron. eyepieces Monocular Binocular. specimen background Bright field Dark field. MICROSCOPES. Resolving Power N.A. affects Wavelength affects. PARTS & TERMS. Lenses (ocular, objective) Total Magnification

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Microscopes

“illumination”

Light (visible)

Fluorescent

U-V

Electron

eyepieces

Monocular

Binocular

specimen background

  • Bright field

  • Dark field

MICROSCOPES

Resolving Power

  • N.A. affects

  • Wavelength affects

MICROSCOPES


Parts terms
PARTS & TERMS

  • Lenses (ocular, objective)

  • Total Magnification

    • ocular mag. X objective mag.

  • Condenser

  • Diaphram

MICROSCOPES


Parts terms1
PARTS & TERMS

  • Numerical Aperture (N.A.)

    optical characteristic of a lens

    N.A. = i sinq

N.A. increases with magnification

MICROSCOPES


Parts terms2

(l innm)

R.P. = wavelength of illumination

(2)N.A.

PARTS & TERMS

  • Resolving Power (R.P.)

    • size of the smallest discernable detail

    • minimum distance between objects so that they are able to be distinguished as separate

[ RP of human eye ~ 0.2mm = ______m ]

MICROSCOPES


Resolving power r p

l = 650nm, NA = 1.25

R.P. = l/2NA = _____nm = _____ m

l = 450nm, NA = 1.25

R.P. = l/2NA = _____nm = _____ m

Resolving Power (R.P.)

l = 650nm, NA = 0.25

R.P. = l/2NA = _____nm = _____ m

1300 1.3

260 0.260

180 0.180

MICROSCOPES


Resolving power r p1
Resolving Power (R.P.)

R.P. = l/2NA

Larger or Smaller R.P. = BETTER ?

  • R.P. improves as N.A. increases or decreases?

  • R.P. improves as l increases or decreases?

MICROSCOPES


Types of scopes
Types of Scopes

MICROSCOPES


Types of scopes1
Types of Scopes

MICROSCOPES


Types of scopes2
Types of Scopes

Compound Light

  • Bright or Dark field

  • Use blue light or blue filter for shorter l

  • R.P. ~ 0.2m

MICROSCOPES


Types of scopes3
Types of Scopes

Fluorescent

  • Dark field compound light microscope

  • Uses U-V for side illumination of specimen, fluorescent parts or dyes give off visible light that is viewed

  • R.P. ~ 0.2m

MICROSCOPES


Types of scopes4
Types of Scopes

UltraViolet (U-V)

  • Uses U-V as illumination (shorter l)

  • Image recorded then viewed… still or video camera image(should NOT look directly at U-V!)

  • Special lens material (quartz),glass absorbs U-V

  • R.P. ~ 0.15m

MICROSCOPES


Types of scopes5
Types of Scopes

Electron Microscopes

  • Use electron beam for illumination, magnets for “lenses”, video to view

  • Transmission Electron Microscope (TEM)

    • beam passes thru, view internal structure

  • Scanning Electron Microscope (SEM)

    • beam reflects, see external structure, texture

MICROSCOPES


Types of scopes6
Types of Scopes

Transmission Electron Microscope (TEM)

MICROSCOPES


Types of scopes7
Types of Scopes

Transmission Electron Microscope (TEM)

  • Special specimen preparation (vacuum)

  • Working magnification:

    whole bacteria….. 8,000x - 10,000x

    thin section, viruses…. 30,000x - 40,000x

  • Maximum magnification ~100,000x

  • R.P. ~0.001m = ______nm

MICROSCOPES


Microscopes

rickettsia

herpes simplex


Types of scopes8
Types of Scopes

Scanning Electron Microscope (SEM)

MICROSCOPES


Types of scopes9
Types of Scopes

Scanning Electron Microscope (SEM)

  • Special specimen preparation(vacuum & conductor)

  • Working magnification:

    14,000x - 50,000x

  • Maximum magnification ~130,000x

  • R.P. ~0.01m = ______nm

MICROSCOPES


Microscopes

Q fever

(rickettsia)

Image

enhancement