Lab Exam 1 Flashcards
Aseptic technique
Tools are sterilized so that bacteria can’t contaminate pure culture
Simple stain
To make bacteria stand out
Chromophore
A colored ion
Basic versus acidic
In basic chromophore is cation
In acidic chromophore is anion
Streak plate method
To obtain pure culture 
Serial dilution
To dilute pure culture enough to be able to count it
Gram stain
Stains
Difference
GP GN
Crystal violet, iodine, ethanol, safranin
Difference: cell wall
GP: purple GN: red
Acid fast stain
Stains
Difference
AF vs NAF
Can cause
Carbol fuchsin, alcohol, methylene blue
Difference: mycobacterium
AF: red NAF: blue
Mycobacterium can cause tuberculosis
Endospore stain
Stains
Difference
S vs V
What forms endospores
Malachite green, safranin
Difference: endospores
Spores(red) vegetative(green)
Bacillus and claustradium
Selective media
Select species to grow inhibit others
Differential media
Shows differences, will change color if able to eat sugar
Mannitol salt agar
MSA
Selects: halophilic (salt loving) staph species
Differential: ferment mannitol
MacConkey agar
MAC
Selective: gram negative
Differential: ferment lactose
Eosin Methylene blue
EMB
Selective: gram negative
Differential: can ferment lactose
Blood agar
Enriched: blood
Differential: hemolytic ability
Alpha- partial- green
Beta- complete- transparent
Gamma- none- no change
