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:
- Label seven 300 ml clear bottles with colors listed above.
- Pour 100 ml of each milk type intwo their respective bottles
- Place bottles on a cart in the prep area until the first lab
- Repeat steps 1-3 each day until the last day of the lab
- 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)
- Obtain one 300 ml clear glass bottl
- 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)
- Repeat steps 1-2 each day until the last day of this lab
- At the end of the two week period there should be a total of 10 labeled bottles