Home
Flashcards
Preview
Clin Lab 4: Microbiology techniques (Gram Staining)
Home
Get App
Take Quiz
Create
Name the 4 reagents used in a gram stain in order of use:CV,GI,D,S
crystal violet
gram's iodine
decolorizer
safranin
A substance that aids in the chemical reaction between the dye and bacteria. Making the dye absorb better.
mordant
Name the mordant
gram's iodine
What is made of acetone or alcohol?
decolorizer
Name the counter stain
safranin
What is made of carbol fuschin?
safranin
Fill in the steps
1.place specimen on glass slide
2.air dry
3.
4.flood slide with crystal violet for 1 min
5.
3.heat fix
5.rinse slide carefully under slowly running water
When heat fixing what should you be sure to do?
pass the slide through the flame several times
When flooding the slide with crystal violet for 1 minute what should you be sure to do?
cover the entire area with stain
Fill in the steps
6.flood stain with gram's iodine for 1 minute(cover entire slide with stain)
7.
8.
7.rinse slide again slowly
8.decolorize slide carefully with alcohol
How long should decolorizer run?
until the slide runs clear
Fill in the
steps
9.
10.flood slide with safranin(counter stain) for 30 sec
11.rinse
12.
9.immediately rinse once the slide runs clear after decolorizing
12.blot slide carefully with paper towl
How long is crystal violet applied to the slide?
1 minute
How long is iodine applied to the slide?
1 minute
How long is decolorizer applied to the slide?
until it runs clear
Should decolorizer be left to set on the slide?
NEVER
How long is safranin applied to the slide?
30 seconds
What powers are used under the microscope?
10x
40x
100x oil immersion
Why do gram + and gram - cells stain differently?
the amount of peptidoglycan in their cell walls
Peptidoglycan provides strength, but what is it made of?
sugar and amino acids
What cells stain purple?
gram + bacteria and yeast
Why do gram + cells stain purple?
they have 5x's the amount of peptidoglycan and this absorbs the crystal violet
What cells stain pink?
gram - bacteria and host cells
In short name the steps of gram staining for review:F-C-R-I-R-D-R-S-R-B
fix
crystal violet
rinse
iodine
rinse
decolorizer
rinse
safranin rinse
blot
What bacteria has the thicker cell wall?
gram + because of the peptidoglycan
What outer layer do gram - bacteria have that gram + bacteria do not?
LPS
What does LPS stand for?
lippolysaccharide layer
Where is the LPS?
it sits on top of the cell wall and is a second membrane
What advantage do gram - bacteria have since they have the LPS?
harder to kill because it increases their resistance to antibiotics
Name the 3 forms of bacteria
coccus
bacilli
spirillum
GPCOC
gram positive cocci
GPROD
gram positive rod
GNCOC
gram negative cocci
GNROD
gram negative rod
What form of bacteria is rare?
spirillum
What is the leading cause of cystitis?
gram - enteric bacilli
pair
diplococcus
gram + grape like cluster
staphyococci
gram + chain
streptococci
cube of 8
sarcinae
cluster of 4
tetrad
What 3 things can bacillus species look like?
long/wide
long/narrow
branched
Mixed populations are harder to kill what should be used?
broad spectrum abx (clavamox,baytril)
Yeast can be what 2 shapes
budding
branching
What are yeast called when they branch?
hyphae
Author
heather.dundas
ID
233995
Card Set
Clin Lab 4: Microbiology techniques (Gram Staining)
Description
vti
Updated
9/10/2013, 11:08:39 AM
Show Answers
Home
Flashcards
Preview