MCB 2610 Lab Practical
What is the process of contamination control? - correct answer ✔Aseptic
technique
What are pipettes - correct answer ✔calibrated glass tubes used to measure
and dispense small volumes of liquids
Petri dishes - correct answer ✔small plastic bins
Swabs. cuvettes, pasteur pipettes - correct answer ✔sharps container
What color is the bigger vs. smaller micropipettors pipettes? - correct answer
✔Green - bigger
Blue - smaller
What is the purpose of isolating bacteria? - correct answer ✔To establish a
PURE CULTURE, to be able to study to study the physiology and morphology
of a particular bacterial type
What is the quickest and most economical method of bacterial isolation? -
correct answer ✔Streak plate method
What must you use to view items under 100x? - correct answer ✔immersion
oil
What does parfocal mean? - correct answer ✔It means that if you focus the
specimen in one objective, it'll be in approximate focus in all objectives
,Parts of the microscope labeled - correct answer ✔Carrying the microscope:
Back handle and bottom of the scope
Hottest part of the flame in a bunsen burner - correct answer ✔Inner cone
What 4 things must always be done before leaving the lab? - correct answer
✔Dispose of all cultures and plates in the appropriate containers
Clean your bench with Wescodyne
Take off and put away your lab coat
Wash your hands for at least 20 seconds
What is a simple stain? - correct answer ✔Staining procedures that only use
one stain
What is a direct stain? - correct answer ✔A simple stain that colors the
bacteria
What is a negative stain? - correct answer ✔Simple stain that stains the
background but leaves the bacteria unstained
gram stain - correct answer ✔very important differential stain - classifies
bacteria based on their cell envelope structure
What is the purpose of heat fixing? - correct answer ✔1. Denaturing bacterial
enzymes to prevent autolysis
2. Enhances the adherence of bacterial cells to microscope slide
, In Gram stains, why can't Gram negative bacteria retain the crystal violet? -
correct answer ✔Because Gram negative bacteria have an outer membrane
and a thinner layer of peptidoglycan, which are easily depolarized and can
only retain the counterstain (Safranin-pink)
What are the 3 most common stain? - correct answer ✔Gram, capsule, and
spore stain
What are stains made of? - correct answer ✔Usually salts, a few acids or
bases, charged ions.
The ion that is colored contains a chromophore group
What is it called if the chromophore is a positive ion (like methylene blue)? -
correct answer ✔Basic stain
What is it called if the chromophore is a negative ion? - correct answer
✔Acidic stain
What causes endospore formation? - correct answer ✔It's a response to
certain environmental conditions such as depletion of nutrients, heating,
drying, and other unfavorable conditions.
Heat used during staining does not cause sporulation
Procedure for gram stain - correct answer ✔Use a wax pencil!
flood violet - 1 min
WASH
What is the process of contamination control? - correct answer ✔Aseptic
technique
What are pipettes - correct answer ✔calibrated glass tubes used to measure
and dispense small volumes of liquids
Petri dishes - correct answer ✔small plastic bins
Swabs. cuvettes, pasteur pipettes - correct answer ✔sharps container
What color is the bigger vs. smaller micropipettors pipettes? - correct answer
✔Green - bigger
Blue - smaller
What is the purpose of isolating bacteria? - correct answer ✔To establish a
PURE CULTURE, to be able to study to study the physiology and morphology
of a particular bacterial type
What is the quickest and most economical method of bacterial isolation? -
correct answer ✔Streak plate method
What must you use to view items under 100x? - correct answer ✔immersion
oil
What does parfocal mean? - correct answer ✔It means that if you focus the
specimen in one objective, it'll be in approximate focus in all objectives
,Parts of the microscope labeled - correct answer ✔Carrying the microscope:
Back handle and bottom of the scope
Hottest part of the flame in a bunsen burner - correct answer ✔Inner cone
What 4 things must always be done before leaving the lab? - correct answer
✔Dispose of all cultures and plates in the appropriate containers
Clean your bench with Wescodyne
Take off and put away your lab coat
Wash your hands for at least 20 seconds
What is a simple stain? - correct answer ✔Staining procedures that only use
one stain
What is a direct stain? - correct answer ✔A simple stain that colors the
bacteria
What is a negative stain? - correct answer ✔Simple stain that stains the
background but leaves the bacteria unstained
gram stain - correct answer ✔very important differential stain - classifies
bacteria based on their cell envelope structure
What is the purpose of heat fixing? - correct answer ✔1. Denaturing bacterial
enzymes to prevent autolysis
2. Enhances the adherence of bacterial cells to microscope slide
, In Gram stains, why can't Gram negative bacteria retain the crystal violet? -
correct answer ✔Because Gram negative bacteria have an outer membrane
and a thinner layer of peptidoglycan, which are easily depolarized and can
only retain the counterstain (Safranin-pink)
What are the 3 most common stain? - correct answer ✔Gram, capsule, and
spore stain
What are stains made of? - correct answer ✔Usually salts, a few acids or
bases, charged ions.
The ion that is colored contains a chromophore group
What is it called if the chromophore is a positive ion (like methylene blue)? -
correct answer ✔Basic stain
What is it called if the chromophore is a negative ion? - correct answer
✔Acidic stain
What causes endospore formation? - correct answer ✔It's a response to
certain environmental conditions such as depletion of nutrients, heating,
drying, and other unfavorable conditions.
Heat used during staining does not cause sporulation
Procedure for gram stain - correct answer ✔Use a wax pencil!
flood violet - 1 min
WASH
