Principles of Staining Flashcards
Colors and contrast of microorganisms in their natural state?
Colorless and lacking of contrast
An auxiliary technique used in microscopy to enhance contrast in the microscopic image.
Staining
Frequently used in biology and medicine to highlight structures in biological tissues for viewing, often with the aid of different microscopes.
Stains and dyes
The process of fixing the microorganism, or killing it, before attaching them to the slide
Fixation
Ways of fixation
Heat-fixing, air-drying, and chemical fixation
Procedure of Simple Staining
Smear microbes to slide -> air-dry -> drip methanol onto specimen to fix -> flood slide with stain -> rinse with water before blotting dry -> examine with x100 objective (OIO)
Type of staining that uses two or more dyes, as well as reacting differently with different microorganisms
Differential staining
Purpose of differential staining
To contrast two or more organisms which maybe of the same or different species
Who developed the Gram Stain
Hans Christian Gram
When was Gram Stain developed?
1884
(Gram Stain Reagent) Primary Stain
Crystal Violet
(Gram Stain Reagent) Mordant
Gram’s Iodine
(Gram Stain Reagent) Decolorizer
Alcohol
(Gram Stain Reagent) Counterstain
Safranin
Gram result that has a thick peptidoglycan
Gram +
Gram result wherein the outer membranes have lipids, polysaccharide
Gram -
Gram result that has 90% peptidoglycan
Gram +
Gram result that has no teichoic acids
Gram -
Gram result that has teichoic acids
Gram +
Gram result that has a thin peptidoglycan
Gram -
Gram result that does not have many polysaccharies
Gram +
Color of Gram + test?
Purple/violet
Color of Gram - test?
Pink/red
Age of the culture the gram stain should be performed on?
18 to 24 hour culture
Bacteria that cannot be seen in Gram staining
thick lipid layer containing mycolic acid (mycobacterium) oand atypical cell wall (mycoplasma)
Who developed the Acid Fast Stain?
Franz Ziehl and Friedrich Neelsen
To which does the acid fast stain binds strongly to?
To bacteria that have a WAXY material in their cell walls
(Acid Fast Reagents) Primary Stain
Carbolfuchsin
(Acid Fast Reagents) Mordant
Heat
(Acid Fast Reagents) Decolorizer
Acid-alcohol
(Acid Fast Reagents) Secondary Stain
Methylene blue
Color of Acid Fast?
Pink/Red
Color of Non Acid Fast
Blue/Purple
Preparing colorless bacteria against a colored background
Negative staIning
Another name for Negative staining
Indirect Staining
Negative staining reagent
Nigrosine or India Pink
Staining procedure used to color, isolate, identify, and study specific parts or structures of microorganisms
Special staining
Types of Special Staining
Flagella Staining, Spore Staining, and Capsule Staining
(Flagella Staining Results) Wet mount staining
Purple MO against lighter purple stain
(Flagella Staining Results) Leifson’s staining
Blue MO against pink/red stain
Flagellar arrangements with one flagella at one end
Monotrichous
Flagellar arrangements with multiple flagella at one end
Lophotrichous
Flagellar arrangements with one flagella at each end
Amphitrichous
Flagellar arrangements with multiple flagella at each end
Petrichous
Special resistant, dormant structure formed within a cell that protects a bacterium from adverse environmental conditions
Endospore
Another name for Endospore Staining?
Schaeffer-Futon Endospore stain
(Endospore Staining Reagents) Primary Stain
Malachite green
(Endospore Staining Reagents) Decolorizer
Acid-alcohol
(Endospore Staining Reagents) Secondary Stain
Safranin
What does Endospore Staining usually identify
Bacillus and Clostridium
Color of Endospore in Endospore Staining?
Green
Color of Vegetative cell in Endospore Staining?
Pink/red
Staining technique that stains the bacteria and the background, leaving the capsule unstained
Capsule staining
Another name for Capsule Staining
Welch Method
(Capsule Staining Reagents) Primary Stain
Congo Red or Nigrosin
(Capsule Staining Reagents) Mild decolorizer
Copper sulfate
Examples of Capsule Staining bacteria
Streptococcus pneumoniae and Cryptococcus neoformans
