LAB MIDTERM Flashcards
(24 cards)
What are the steps of a negative stain?
Mix your sample and nigrosin, air dry, and then examine the bacteria
What stain is used for a negative stain?
nigrosin
What are the steps of a capsule stain?
Mix your sample with Congo Red, air dry, flood slide with acid alcohol, use acid fuchsin for 2 min and rinse with water, air dry and examine
What stain is used for a capsule stain?
Congo Red
What are the bacteria that we used in lab for a capsule stain?
Klebsiella pneumoniae is capsule positive
Staphylococcus is capsule negative
What are the bacteria used for a acid fast stain?
Mycobacterium smegmatis- acid fast positive (pink)
Staphylococcus aureus- acid fast negative (blue)
What stain do you use for a acid fast stain?
carbol fuchsin , methylene blue
What are the steps of a acid fast stain?
Put bacteria on slide, air dry and heat fix, put a paper towel on top of sample and steam the smear for 5 minutes, continuously adding carbol fuchsin. remove the paper towel and rinse with water, and then rinse with acid alcohol for 15 seconds, counterstain with methylene blue and look under microscope
What bacteria was used in lab for a spore stain?
Bacillus sublitis- spore positive (spores are green)
Staphylococcus aureus- spore negative (red)
What stains were used for spore stain?
Malachi Green, safranin
What are the steps of a spore stain?
Put sample on slide (air dry and heat fix), put paper towel on slide, steam slide for 5 minutes while putting Malachi green on it, remove paper towel and rinse with water. Use safranin for 1 minute and wash and dry
What is the procedure of getting a mold sample?
touch tape to mold and tape it to the slide, on drop of cotton blue on top of tap and put cover slide on top of blue. Put over flame until blue starts boiling and look under the microscope.
What was the mold sample that was used?
Rhizopus
What was the yeast that we used in class?
Saccharomyces cerevisiae
What is the procedure to get the yeast?
One drop of Sacch on slide (air dry and heat fix), and one drop of methylene blue with the cover slip
What are the 3 types of mold that we observed in lab?
Rhizopus- bread mold
Aspergillum- black mold
Penicillium- makes penicillin
For the motility test, what were the two bacteria that we used?
Proteus mirabilis- motile (moves a lot)
Staph. aureus- not motile (moves very little)
What is the point of the hanging drop slide?
purpose is the see the bacteria swimming around without staining the bacteria
With the thioglycolate broth, what are the 4 organisms that we observed?
Clostridium- strict anaerobe
Staph- facultative anaerobe
Strep- microaerophile
Bacillus- strict aerobe
What does a strict anaerobe mean?
doesn’t like oxygen (Clostridium)
What does a facultative anaerobe mean?
can grow in oxygen and without oxygen (Staph)
What does a microaerophile mean?
likes lower levels of oxygen (Strep)
What is a strict aerobe?
needs oxygen to survive (Bacillus)
What is the dilution factor of plate 3 and 1/10ml?
10^7
