portage learning, Biod 171, Micro Lab Exams.latest 2022 Answers

portage learning, biod 171, micro lab exams, with updated answers. 1. What three elements are used in an autoclave to sterilize equipment? heat, pressure, and steam 2. What is the minimum temperature an autoclave must be set at to achieve sterile condition? 125°C 3. If you are working in a lab in which an autoclave is not available, and you are pressed for time, which would you chose to best sterilize your equipment? Hot steam or hot air? Explain why you chose your answer. Hot steam is the best choice as you can achieve a sterile environment in a matter of minutes whereas hot air will take several hours to achieve the same effect. 4. What type of incubator is pictured below? Fixed incubator 5. At what temperature is the fixed incubator set to, as presented in the lab video? 37°C LAB 3 EXAM 1. List the 4 main steps used to prepare a WET mount and indicate which (if any) step is optional. 1 – Clean slide 2 – Circle area on slide with wax/hydrophobic pen 3 – Apply organism to slide 4 – View under microscope *Note: there are no optional steps in the wet mount. 2. When preparing a glass slide for a dry mount, what cleaning solution was used? 70% ethanol 3. You wish to study the motility of a particular bacterium. What type of mounting technique would you use? Explain your answer. A wet mount technique is the best technique to use when studying motility of an organism because the sample remains viable (heat fixing kills the sample). 4. What dye do Gram-negative bacteria primarily retain? Safranin 5. Why are Gram-positive bacteria able to retain the crystal violet dye? They contain a thick peptidoglycan layer in their cell wall that readily retains the dye. 6. Identify the Gram status (positive or negative) and shape of the bacteria pictured below. Gram- Negative; Bacillus (rod) 8. If you were required to grow 4 types of bacteria on a single agar plate without cross contaminating the samples, what method would you use? Quadrant growth method 9. Based on the 4-phase dilution streaking experiment, in what phase were bacterial isolates (colonies) observed? Individual colonies were observed within Phase 3. 10. Identify the plating method (below) as demonstrated in the lab. Quadrant growth