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Lab 10: Worksheet

  • Page ID
    24051
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    Name: ______________________________

    Section: _____________________________

    Student ID#:__________________________

    Work in groups on these problems. You should try to answer the questions without referring to your textbook. If you get stuck, try asking another group for help.

    Plague Assay

    Record your results below. A countable plate has between 30-300 plaques. If there are more than 300 plaques record TMTC (too many to count), if there are fewer than 30 plaques record TFTC (too few to count) (1).

    A B C D E F G
    Plaques Counted
    Sample Volume 2.5 mL. 2.5 mL. 2.5 mL. 2.5 mL. 2.5 mL. 2.5 mL. 2.5 mL.
    \(\frac{PFU}{mL}\)
    \(\frac{PFU}{mL\;of\;starting\;tube}\)

    1. Why is it important in this assay to make sure that there are enough bacteria present to produce a lawn? (1)

    2. What would happen if you had not waited the 15 minutes that the protocol requires? (1)

    3. Why was the water bath set to 50°C? (1)

    4. What is the difference between a CFU and a PFU? (1)


    Lab 10: Worksheet is shared under a CC BY-SA license and was authored, remixed, and/or curated by Nazzy Pakpour & Sharon Horgan.

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