Lab Exam 1 Flashcards
what are some objects that are regularly flamed to avoid contamination?
opening of glass tube of microbes
loop tool
what is the power of the ocular lens?
10x
what are the powers of the four objective lenes of the microscope?
4x
10x
40x
100x
what is the smallest total magnification and the largest total magnification our compound microscope can magnify?
40x - 1000x
what is the purpose of oil immersion?
reduces light refraction which limits loss of light in order to view clear image (increase the resolution) at 1000x magnification
which objective lens requires immersion oil?
100x
what is a smear? Is microbe alive?
fusing of a microbe to a glass slide
microbes are dead
what is a wet mount? is microbe alive?
liquid sample containing Living culture of microbes
yes
what are the steps of making a smear?
- take two loopfuls of bacteria to target circle
- air dry
- heat fix by running slide through flame 6 times
what is the purpose of fusing bacteria to slide?
kills bacteria
makes bacteria easier to see because they are not moving
WHAT do we flame during preparation of smear? why?
-opening of microbe vile
- looping tool
to follow aseptic technique and not contaminate microbes to other surfaces or the microbes themselves
what is the advantages of using a wet mount instead of a smear?
live organisms (you can see how they function)
easy to prep
why do we stain microbes?
to better see morphology (size and shape)
How is simple stain different than a differential stain?
simple stain uses one dye
differential stain uses multiple dyes
what are the names and colors of the simple stains we used at beginning of class?
methylene blue (blue)
safranin (pink)
what are the basic steps to differential stain technique?
- start with applying primary stain to smear
- use mordant
- use decolorizer
- use counterstain
what is a mordant’s purpose?
helps dye color stick in target cells (intensifies color)
what is the decolorizer’s purpose?
removes color from the background and any non-target cells
what is the counterstain’s purpose
stains non-target cells
what is the reason to use a differential stain technique?
to help see and differentiate different microbes
during which step is the simple stain used within the differential staining technique?
last step = secondary/differential stain
during which step is the differential stain used during the differential staining technique?
first step = differential stain
would malachite green be considered a simple or differential stain?
differential
what is the primary stain in the spore staining technique?
malachite green
what is the mordant in the spore staining technique?
steam
what is the decolorizer in the spore staining technique?
distilled water
what is the counterstain in the spore staining technique?
safranin
what are two genera of common spore formers?
what is the color of the endospores at the end?
endospores are green
what appears to be pink at the end of endospore staining?
vegetative cells
what is the primary stain in gram staining?
crystal violet
what is the mordant in gram staining?
iodine
what is the decolorizer used in gram staining?
alcohol and acetone
what is the counterstain used in gram staining?
safranin
what color is a Gram positive cell at the end of stain?
purple
what color is a Gram negative cell at the end of stain?
pink
what are the shapes and genera of the two Gram bacteria we used?
Staphylococcus - coccus
Escherchia - bacillus
what is the primary stain in acid-fast staining?
basic fuchsin
what is the mordant in acid-fast staining?
phenol + dimethyl sulfoxide
what is the name when basic fuchsin is mixed with the mordant in acid-fast technique?
carbol fuchsin