Skip to main content
Biology LibreTexts

13.2: Community Ecology Lab (Instructor Materials Preparation)*

  • Page ID
    41824
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Lab Materials

    This is the prep for one section of 24 students.

    Ecological Succession of Bacteria in Milk

    Students will do this part in table teams (groups of 4).

    Materials Quantity Notes
    clean microscope slides 1 box  
    coverslips 1 box  
    Bunsen Burner 1 per table  
    tubing for Bunsen Burners 1 per table  
    wire loop 1 per table  
    50 ml beaker 3 per table  
    pH probe 1 per table can use pH paper as an alternative
    compound light microscope 1-2 per table  
    clothespins 2 per table to hold slides for gram staining procedure
    gram staining kit 1 per table includes Safranin, Crystal violet, Iodine and ethanol
    Bunsen striker 1 per table  
    squirt bottle of DI water 1 per table  

    Side bench for students to share: empty milk containers with nutritional information: whole milk, 2%, 1%, skim, chocolate, whole buttermilk and reduce fat buttermilk

    Side bench for students to share: 1L beaker of 10% bleach solution (to disinfect slides are staining)

    1 week prior to lab purchase the following:

    • Whole milk: 1 gallon (red tape)
    • 2% milk: 1/2 gallon (white tape)
    • 1% milk: 1/2 gallon (green tape)
    • Skim milk: 1/2 gallon (blue tape)
    • Chocolate milk; 1/2 gallon (brown tape)
    • Whole buttermilk: 1/2 gallon (yellow tape)
    • Reduced fat buttermilk: 1/2 gallon (orange tape)

    Milk set up:

    1. Label seven 300 ml clear bottles with colors listed above.
    2. Pour 100 ml of each milk type intwo their respective bottles
    3. Place bottles on a cart in the prep area until the first lab
    4. Repeat steps 1-3 each day until the last day of the lab
    5. At the end of the two week there should be a total of 70 labeld bottles

    Milk in incubator (should be set at 37 C)

    1. Obtain one 300 ml clear glass bottl
    2. Pour 100 ml of whole milk into the bottl and place in the incubator (whole milk is the only type to go in the incubator)
    3. Repeat steps 1-2 each day until the last day of this lab
    4. At the end of the two week period there should be a total of 10 labeled bottles

    Contributors and Attributions

    CC licensed content, Original

    This page titled 13.2: Community Ecology Lab (Instructor Materials Preparation)* is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Lynette Hauser via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.

    • Was this article helpful?