BIOL 2051 LAB FINAL PRACTICE QUESTIONS
WITH DETAILED EXPLANATIONS 2026
◉ What does the PowerBead Tube contain?
Answer: a buffer
◉ What does the buffer in the PowerBead Tube do?
Answer: 1. helps disperse sample particles
2. begins to dissolve humic acids
3. protects nucleic acids from degradation
◉ C1 solution?
Answer: contains SDS (sodium dodecyl sulfate) which CHEMICALLY
lyses cells to get the DNA out
◉ C2 solution?
Answer: removes impurities from DNA, which go into the pellet
following centrifugation
◉ C3 solution?
Answer: same as C2
,◉ C4 solution?
Answer: high [salt] solution to adjust [salt] concentrations of DNA
solution to allow tighter binding of DNA to Spin Filters (silica)
◉ C5 solution?
Answer: ethanol-based wash solution that removes excess salt and
further purifies DNA while allowing it to remain bound to silica
membrane of Spin Filter
◉ C6 solution?
Answer: sterile elution buffer ensures entire silica Spin Filter
membrane is wetted, resulting in a more efficient and complete
release of DNA from silica upon centrifugation
◉ Gram stain
Answer: 1. crystal violet
2. iodine
3. ethanol
4. safranin
+ purple
- pink
,◉ Endospore stain
Answer: leave on slide warmer and put paper towel square on top of
smear
1. malachite green
take off warmer then remove paper towel once cooled.
2. safranin
endospore: green
vegetative cell: pink/red
◉ Acid-Fast stain
Answer: 1. add egg albumin, then add & mix in Mycobacterium
smegmatis, then add E. coli. heat fix
leave on slide warmer and put paper towel square on top of smear
2. carbol fuschin
take off warmer then remove paper towel once cooled.
3. acid alcohol
4. methylene blue (2 min)
Acid-fast: red
Non-acid-fast: blue
, ◉ Capsule stain
Answer: 1. small congo red drop on clean slide, then add, mix, &
spread culture
2. dry at ROOM TEMP.
3. Maneval's stain (2 min)
Encapsulated cells (ex: Azotobacter vinelandii): purple cells
surrounded by white "halo" (capsule)
◉ Mycobacteria sp.
Answer: -aerobic
-non-sporulating
-non-motile
-RODS
◉ killit ampoule
Answer: test ampoule would appear TURBID and YELLOW if
autoclave didn't reach 121° C b/c endospores would be able to
germinate into vegetative cells, which would ferment (using carbs.
from the nutrient broth), thus releasing lactic acid.
◉ Proteus vulgaris
Answer: peritrichous flagella, rod-shaped cells
WITH DETAILED EXPLANATIONS 2026
◉ What does the PowerBead Tube contain?
Answer: a buffer
◉ What does the buffer in the PowerBead Tube do?
Answer: 1. helps disperse sample particles
2. begins to dissolve humic acids
3. protects nucleic acids from degradation
◉ C1 solution?
Answer: contains SDS (sodium dodecyl sulfate) which CHEMICALLY
lyses cells to get the DNA out
◉ C2 solution?
Answer: removes impurities from DNA, which go into the pellet
following centrifugation
◉ C3 solution?
Answer: same as C2
,◉ C4 solution?
Answer: high [salt] solution to adjust [salt] concentrations of DNA
solution to allow tighter binding of DNA to Spin Filters (silica)
◉ C5 solution?
Answer: ethanol-based wash solution that removes excess salt and
further purifies DNA while allowing it to remain bound to silica
membrane of Spin Filter
◉ C6 solution?
Answer: sterile elution buffer ensures entire silica Spin Filter
membrane is wetted, resulting in a more efficient and complete
release of DNA from silica upon centrifugation
◉ Gram stain
Answer: 1. crystal violet
2. iodine
3. ethanol
4. safranin
+ purple
- pink
,◉ Endospore stain
Answer: leave on slide warmer and put paper towel square on top of
smear
1. malachite green
take off warmer then remove paper towel once cooled.
2. safranin
endospore: green
vegetative cell: pink/red
◉ Acid-Fast stain
Answer: 1. add egg albumin, then add & mix in Mycobacterium
smegmatis, then add E. coli. heat fix
leave on slide warmer and put paper towel square on top of smear
2. carbol fuschin
take off warmer then remove paper towel once cooled.
3. acid alcohol
4. methylene blue (2 min)
Acid-fast: red
Non-acid-fast: blue
, ◉ Capsule stain
Answer: 1. small congo red drop on clean slide, then add, mix, &
spread culture
2. dry at ROOM TEMP.
3. Maneval's stain (2 min)
Encapsulated cells (ex: Azotobacter vinelandii): purple cells
surrounded by white "halo" (capsule)
◉ Mycobacteria sp.
Answer: -aerobic
-non-sporulating
-non-motile
-RODS
◉ killit ampoule
Answer: test ampoule would appear TURBID and YELLOW if
autoclave didn't reach 121° C b/c endospores would be able to
germinate into vegetative cells, which would ferment (using carbs.
from the nutrient broth), thus releasing lactic acid.
◉ Proteus vulgaris
Answer: peritrichous flagella, rod-shaped cells
