6. Microbiology and Biotechnology
Lab Techniques — Quiz
Test your understanding of lab techniques with 5 practice questions.
Practice Questions
Question 1
A student plates 0.2 mL of a 10^{-4} dilution of a bacterial culture and incubates it. After incubation, 80 colonies are observed. What is the concentration of the original culture in CFU/mL?
Question 2
What is the principle behind membrane filtration used to sterilize heat-sensitive liquids?
Question 3
During Ziehl–Neelsen acid-fast staining, heat is applied after adding carbolfuchsin. What is the purpose of this heating step?
Question 4
A student uses a microscope with numerical aperture NA=1.25 and green light at λ=550 nm. According to the Abbe equation, what is the theoretical resolution limit d?
Question 5
Which component in a phase-contrast microscope is responsible for creating contrast by shifting the phase of background light relative to light diffracted by the specimen?