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Lab 9: Worksheet

  • Page ID
    24031
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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.

    1. For your dilution plates draw your results below. (1)

    clipboard_e0d32eb6603abeba0e641e82a97392844.png

    2. Calculate the original CFUs in your original broth tube, if you are within 500 CFUs of what Dr. Pakpour calculated you can earn 5 extra credit points! (1)

    3. A plate has 72 colonies with a total dilution factor of 10-7, 100 uL was pipetted onto the plate, what was the original CFU concentration of that sample? (1)

    4. How do you know if you have a ‘countable’ plate when doing a dilution series? (1)

    5. Two plates received 100 uL of the same dilution tube. The first has 293 colonies and the second has 158 colonies. Suggest a reasonable reason why this happened. (1)


    Lab 9: 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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