3.6: Simple Stain
- Page ID
- 90983
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Preparation
- Have test tubes with sterile TSB on hand.
- 24 hours before the laboratory, inoculate test tubes of sterile TSB with a bacterial species of your choice (Escherichia coli or Staphylococcus aureus are good options) and incubate at the appropriate temperature for that species (37 °C for the E. coli and S. aureus).
Remember that you will have multiple groups needing these cultures so make enough cultures so each group has their own or enough so each group only shares the culture with another group.
You can use multiple bacterial species to have students compare different cell morphologies and arrangements. The Results & Questions section of this lab will require editing to provide questions for multiple species.
Materials
- 24-hour bacterial cultures of choice in TSB - see Preparation section above
- plain microscope slides (at least 1 per group)
- Bunsen burners (1 per group)
- inoculating loops (1 per group)
- (if using bacteria on solid medium rather than TSB) droppers with saline, DI water, or distilled water
- slide warmer
- test tube racks (1 per group plus one or more racks to hold cultures)
- wood test tube clamps/holders (1 per group)
- small chemical waste containers (1 per group)
- methylene blue in a dropper bottle (1 per group or enough for two groups to share one bottle)
- distilled or DI water in squirt bottles (1 per group)
- bibulous paper (enough for each groups to blot their slides)
- light microscopes (1 per group)
- colored pencils
- (optional, but recommended) Wax pencils (1 per group)
- (if using oil immersion) immersion oil dropper bottles
- (if using oil immersion) lens paper