chapter 2 objectives Flashcards
5 I’s of microbiology
inoculation, incubation, isolation, inspection, identification
inoculation
bringing microorganisms into a culture media
incubation
introducing microorganisms to a temperature controlled chamber to encourage the multiplication of microbes
isolation
once cultures have grown, they may need to be re-inoculated and re-incubated so the separate species are obtained
inspection
the act of observing microscopically and macroscopically and possibly staining as well
identification
the identity of an isolated microbiome is identified
3 physicals states of culture media
semisolid, solid, transport
selective vs. differential media
selective: designed to promote growth of certain organisms and suppress others
differential: multiple types grown but visibly different
best method for colony isolation
streak plating
3 pioneers of microscopy
Galileo (created microscope by modifying telescope), Hooke (discovered microorganisms with the compound microscope), and Leeuwenhoek (found “animals” in drops of water and “animalcules” from teeth)
resolution
ability of an optical system to differentiate between two adjacent objects/points from each other
contrast
the difference in light intensity of the specimen relative to its background
real image
the image formed by the objective
virtual image
formed by the image projected up through the microscope body to the eyepiece where the ocular lens forms the second image
purpose of oil immersion lens
increase resolution when increasing magnification objective
3 elements of good microscopy
magnification, resolution, and contrast.
3 types of light microscopes
bright-field (light through specimen)
dark-field (blocks all light)
phase contrast (light waves)
2 types of uv microscopes
fluorescence (ultraviolet light)
confocal (high resolution with fluorescent probes)
2 types of electron microscopes
transmission electron (beam of electrons
scanning electron (focused electron beam)
simple stain example
methylene blue (flooding with basic dye)
differential stain example
gram staining (2 different dyes)
special stain example
acid staining (target a specific bacteria)
steps of gram stain
- stain microorganism with crystal violet (positive and negative appear violet)
- add iodine which will slightly change color on both to blue purple
- alcohol wipe is applied to both grams because gram positive keeps its stain whereas gram negative looses it
- add safranine where gram positive remains purple and gram negative turns pink/red
difference between cell wall of gram negative/gram positive
gram negative has thinner 2D peptidoglycan layer with no teichoic acid
gram positive has thicker peptidoglycan layer with teichoic acid
color of gram positive and gram negative organism
gram positive: purple/blue (thicker peptidoglycan layers in cell walls)
gram negative: pink/red (thinner peptidoglycan layers in cell walls)
acid fast stain use
Used to identify bacteria that have a waxy (lipid) layer
spore stain use
Used to detect endospores, typically found in bacteria
capsule stain use
Used to visualize the presence of capsules surrounding certain bacteria, aiding in their identification and understanding their virulence
flagella stain use
Used to highlight the presence and arrangement of flagella, aiding in the characterization of motile bacteria
fluorescense stain use
Utilized to detect specific molecules or structures within cells using fluorescent dyes.
