Micropara lab midterms Flashcards
Simple staining uses how many dyes?
1
What dyes are used in positive simple staining
Basic dyes
What dyes are used in negative simple staining
Acidic dyes
Use two or more dyes that will distinguish bacteria from each other because their walls have different reactions on dyes
Differential staining
Using staining, what else can you see in the structural components of bacteria? Name 3
Flagella, capsules, and granules
For positive staining, what color should the microorganism be?
dark blue to violet with a bright background
For negative staining what color should the microorganism be?
Colored with a colorless wall in a dark background
What color is a gram positive bacteria?
Blue to violet
What color is a gram negative bacteria?
pink to red
What is the mordant used for gram staining
Gram Iodine
What is the primary stain used for gram staining
Crystal violet
What is the decolorizer used for gram staining?
Ethanol
What is the secondary stain used for gram staining?
Safranin
What are the different forms for characterization of colonies
Punctiform, circular, filamentous, rhizoidal, irregular
What are the different margins for characterization of colonies
Entire, undulate, lobate, filamentous, rhizoid
What are the different Elevations for characterization of colonies
Flat, raised, convex, pulvinate, umbonate
What are the different Surfaces for characterization of colonies
Smooth, contoured, concentric, wrinkled
What are the different consistencies for characterization of colonies
Butyrous, viscid, brittle
What are the different transparencies for characterization of colonies
Opaque, Translucent
This occurs when microorganisms enter a culture medium in which a pure culture of microorganism is growing
Contamination
Isolation of bacteria into ______ is the best way to study and characterize bacterial cultures
Pure form
How is isolation of bacteria into pure form accomplished?
By spreading sample containing microorganisms on a solid medium so that a single cell occupies a well-isolated portion of agar surface
What are cultures consisting of a single species
Pure cultures
What are three common techniques used in isolation of bacteria
Streak plating, spread plating, and pour plating
In this plating, inoculum is spread over the surface of the medium by the inoculating loop
Streak plating
In this plating, it uses an L-shaped rod to spread the inoculum over the entire plate
Spread plating
In this plating, a medium is poured into the plate with an inoculum and allowed to solidify
Pour plate
What plating is used to isolate and purify bacteria?
Streak plating
What plating is used to isolate aerobic microorganisms?
Streak and spread plating
What plating is used to isolate anaerobic microorganisms?
Pour plate
For streak and spread plating, you should incubate the plates in what manner?
Inverted manner
Important criterion used to establish the quality of food and dairy products
Bacterial counting/ Measuring size of a microbial population
Measurement of the size population is done by
Counting the number of individual cell or by counting the number of viable cells that can form colonies on agar suface
This is also known as counting chamber, is easy, inexpensive and relatively quick
Direct count
Direct count gives information on?
The size and morphology of microorganisms
Also known as the plating technique and is the most widely used because of the ease in counting the colonies and the manipulation of microscope is not required
Viable Count
What dilution is used for spread plate?
0.1
What dilution is used for pour plate?
1.0
