Introduction
􀁡microscopy
Introduction
􀁡microscopy
􀁡most cells are .01-.1 mm
􀁡unaided eye sees .1mm
􀁡Hooke
􀁡built microscope (30X)
Purpose of Microscope
􀁡magnification
􀁡 enlarged image by a factor
􀁡resolving power
􀁡 ability to separate two adjacent points in a
specimen
􀁡contrast
􀁡 how well details stand out against the
background
􀁡parfocal
􀁡remain in focus when switching objectives
Rules and Care of the
Microscope, abridged
􀁡carry microscope correctly
􀁡clean lenses with lens paper and slides
with Kimwipes
􀁡set smallest objective in place (4X) and
bring stage close of objectives
􀁡use oil with oil immersion lens (100X) only
􀁡clean all lenses when finished
􀁡have instructor check scope before storing
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The Compound Microscope
Metric measurement of a field of view
􀁡ocular = 10X
􀁡mag of lens total mag. (ocular x obj.)
4X 40X
10X 100X
40X 400X
100X 1000X
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6
Exercises
Ex. 7.1 fill in table
Ex. 7.2 depth of focus:
colored threads,determine order
Ex. 7.3 image orientation
letter “e” ; draw at 40x and 100x
􀁡Ex. 7.4 dissecting microscope
􀁡Observe bacterial culture dish
Other Microscopes
• 􀁡dissecting,greater working
distance,reflected and transmitted light
• 􀁡light microscope
• 􀁡phase contrast microscope
• 􀁡transmission electron microscope, TEM
• 􀁡scanning electron microscope, SEM
Cell Theory
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Cell Theory
􀁡all organisms are made of cells
􀁡the cell is the smallest living thing
􀁡all cells arise from pre-existing cells
Eukaryotic Cells
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Plant : Elodea cells w/ water
draw and label @ 400X total mag.
Label nucleus ,plasma membrane
cytoplasm w/ cytosol,cell wall of cellulose
Chloroplast,vacuole
Eukaryotic Cells
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Plant : Onion bulb cellsw/ iodine
􀁡draw and label @ 400X total mag.
Label nucleus w/ DNA,plasma membrane
cytoplasm w/ cytosol,cell wall of cellulose
Nucleolus,vacuole
Eukaryotic Cells
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Animal : human cheek cells
w/ methylene blue stain
draw and label @ 400X total mag.
nucleus w/ DNA, plasma
membrane,cytoplasm w/ cytosol
Prokaryotic Cells
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􀁡label cell,cell wall of peptidoglycan
plasma membrane,cytoplasm w/ cytosol
Ribosome,nucleoid w/ DNA
draw three basic shapes
determine stain reaction
Gram positive = purple
Gram negative = red
Models
Study both animal and plant cell
models
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