Microbiology Lab [ LAB EXAM 1 ] Review
At the end of Gram staining, Gram positive bacteria stain purple while Gram negative bacteria stain red.
TRUE
Presence of flagella contributes to bacterial pathogenecity.
TRUE
turns red in reduced form
Tritetrazolium chloride
What is the purpose of using decolorizing agent in Gram staining?
a. In Gram negative cells alcohol increases the porosity of cell wall by dissolving the lipid in outer layer, removing the CV-I complexes b. In Gram positive cells alcohol dehydrates cell wall and shrinks the pores, making it difficult to remove CV-I complexes. >> both a and b are correct <<
In staining procedure used to identify Mycobacterium smegmatis, the decolorizer used is _______
acid alcohol
Negatively charged chromatogens
acidic stains
Primary stain in Acid-fast staining
carbol fuchsin
A streptococcus arrangement shows __________
cocci in chains
Use of two dyes
differential staining
depression slide
hanging drop technique
study of cell shape and arrangement is called ________
morphology
brownian movement
non motile bacteria
group of cocci arranged in cluster of 8
sarcinae
Use of a single stain
simple staining
irregular group of round bacteria with no specific arrangement
staphylococcus
a chain of round bacteria
streptococcus
If a bacterial cluster appears as a square of four cocci, this arrangement is called as _________
tetrad
diplobaccilus
two rod shaped bacteria attached together
What is the concentration of agar in the motility test media?
0.3%-0.5%
concentration of agar
0.3%-0.5%
Why are bacteria not stained in negative staining?
Both the bacterial cell wall and the dye are negatively charged, so they repel each other
Primary stain in Gram staining
Crystal violet
Differential staining
Decolorizing agent
All bacteria have flagella
FALSE
Amphitrichous flagellar arrangement show presence of a cluster of flagella at one end only
FALSE
The proper procedure for smear preparation is:
Make smear-->air dry-->heat fix
Counter stain in Acid fast staining
Methylene blue
Basic stains with a positively charged chromatogen
Methylene blue and Crystal violet
Acidic stain
Nigrosin
Counter stain in Gram staining
Safranin
