Baccilus
Long rod like image under scope
Spirilli
spiral looking circles under scope
Cocci
circular blobs under scope
What type of microscope are we using in class?
Light Microscope
How much does your ocular lens magnify the object
10x
Total Magnification
= 4x * 10x = 40X
RP Equation
550 nm/ 2 * numerical aperture
What is the purpose of oil used in 100x
light bends as it goes from sample to air, oil prevents light scatter
What is the smallest size object that can be clearly seen
220 nm, maximum resolution
Microscope part- Condenser
moves light up and down
Why do we stain bacteria prior to microscopic examination?
increase contrast to be more easily seen
What is the purpose of heat fixing?
to kill the organism, make it adhere to the slide, and alter the organism so that they accept stains
Gram Stain
differentiating bacterial species between gram-positive and gram-negative. Based on Cell wall composition.
Peptidoglycan
is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of bacteria (but not Archaea), forming the cell wall.
Gram positive color
purple
Gram negative color
colorless, thinner Peptidoglycan.
Acid Fast Stain (differential)
Mycobacteria from other bacterial genera
Capsule Stain (structural)
capsule or slime layer
Endospore stain (Structural)
whether bacteria produces spore
Flagella stain (structural)
have flagella and are motile