Lab 1 & Lab 2A- Study Quiz Flashcards
Adjust the ocular lenses distance to accommodate your individual ____ _____.
interpupillary distance
After ______ (last step), as a result of this dilution technique, individual colonies of microbes can be obtained.
incubation
As the magnification of the objective lens increases, so does the _____ ______.
numerical aperture
Endospores are most commonly found in …
Bacillus sp. & Clostridium sp
low G+ C Gram positive bacteria
2 correct responses:
In acid fast bacterial staining procedures…..
=It depends on mycolic acid (It reinforces the cell wall and makes the bacterium resistant to certain chemicals and dyes)
=The Kinyoun stain can be used to stain Nocardia species and Crytosporidia
culture/ cultured means
grown / growing
Each individual colony represents the descendants of a ___ ___.
Single Cell
How do you find the magnification?
Ocular lens X objective lens
How do you refocus the new image after changing to higher magnification?
Use the fine adjustment knob
If you are determining a bacteria morphology, what are you going to focus on?
shape, size, & arrangement
If your CONTROL test tube is CLOUDY, what does this mean?
You did not correctly use the aseptic techniques. It should remain clear. It is the controlled tube, so it shouldn’t grow anything.
In numerical aperture (n* sin a), (sin a) is ___ of the ___ ___ of the image forming rays of the objective lens.
1/2, acceptance angle
In numerical aperture (n * sin a), the (n) is ?
The refractive index or index of refraction
Refractive index
measure of the bending/ “refraction” of a ray of light when passing from one medium into another.
In the Gram Stain, Iodine is used as the____?
Mordant
Mordant
Substance used to set or stabilize stains or dyes.
Example: Iodine acts like a trapping agent that complexes with the crystal violet, make the crystal violet-iodine complex clump and stay contained in thick layers of peptidoglycan in cell walls.
List the basics of aseptic techniques that are used in lab…
Autoclave or steam sterilization of all equipment and media.
Flame sterilization of wire loops and needles which are used to transfer bacteria from one growth condition to another.
Flaming the mouth of test tubes and other containers to establish hot air convection out of the container, to reduce the chance of microbes entering the tube by air flow.
Numerical Aperture
Related to the angles of light which are collected by lens.
—> NA= “n sin a” where (n )is the refractive index and (a) is half the acceptance angle of the image forming rays of the objective lens.
Resolution is dependent on the _A__ of light used (in um),
the _B__ quality, and the refraction and _C__ of light as it passes through the object and air
A. wavelength
B. lens
C. reflection
The Bunsen burner should be adjusted so that you can see __A_ flames.
The dark blue flame is in the __B_ of the flame.
The light blue flame is at the __C_ of the flame.
A. 2
B. center
C. top
The direction of stage movement is ______ to that of the field movement.
Opposite
The standard method of obtaining a “PURE CULTURE” is the
___ ____ method on agar.
Streak-plate
The ____ is below the stage on a microscope.
Condenser
True or False: The resolution of a light microscope is the smallest distance between two adjacent points capable of being distinguished on a slide.
True
Inoculated
introduced
How many objective lens are on the microscope in our lab?
List their magnification
4 objective lens 4x=40x 10x=100x 40x=400x 100x=1000x
Pathology of bacteria means…
ability to cause disease
What is the purpose of the CONDENSER
Focus light onto the specimen
What is a “PURE CULTURE”?
Uncontaminated culture
What is differential stain procedure?
stain procedure consists of at least two different dyes which highlight a biochemical reaction within the cell. It shows more than just simple cell structures.
What is resolution?
the smallest distance two closely adjacent objects can be clearly distinguished with the lens system that is set up
What are the two properties that determine image quality?
Magnification / Resolution
What is simple stain procedure?
consists of only one dye to increase cell contrast from a slide background. It shows simple cell structure.
What is the process of growing pure cultures and is essential for proper characterization of a bacterium?
aseptic (sterile) technique
_______ has to be performed without adding other microbes or contaminates.
inoculation
What is the formula used to calculate resolution? What does (λ) mean? What does NA stand for?
Resolution = λ / (2xNA) where λ = wavelength of light in μm (microns) NA = numerical aperture (+0)
Where is the numerical aperture found?
Numerical aperture is etched onto the objective lens next to that lens’ magnification.
The smallest resolution of the light microscope can be obtained with:
The shortest wavelength of visible light used and an objective lens with the maximum numerical aperture
What is the total magnification of a slide field if you are visualizing that field with the 40X objective lens?
400X magnification.
How do you find total magnification?
ocular lens (10x) X objective lens (4x, 10x,40x,100x)
What is the correct order of reagent use when performing a Gram stain?
crystal violet, iodine solution, acetone alcohol, safranin
Basic stains have a positively charge auxochrome? T or F
TRUE
Negative stains are attracted to glass. T or F
True
Positive stains are attracted to cell contents. T or F
True