Wednesday (12/7) Ilde showed Tomie and I the 3 quadrant inoculation technique, which Tomie posted a picture of. Using this technique, we took two new samples from each cheese and put them in the incubator. Then, we gram stained bacteria cultures from last week's plates (FYI: gram staining is a method for staining samples of bacteria that differentiates between the two main types of bacterial cell wall). We started off by placing 1-3 drops of DI water on a microscope slide and mixing a small amount of bacteria to it (using an inoculation loop), we did this for eight cultures. We waited for the slides to air-dry, then began the actual staining process...
Stain/dye with Gram Crystal Violet for 30 seconds
Rince with distilled water for 5 seconds
Use trapping agent, Gram Iodine for 60 seconds
Rinse with distilled water for 5 seconds
Use Gram Decolorizer for 1-5 seconds
Rinse with distilled water for 5 seconds
Stain/Dye with Gram Safranin for 30 seconds
Rinse with distilled water for 5 seconds
(Note: Only enough drops to cover the dried bacteria is needed)
We didn't get to slide eight because we left to meet with Mrs. Chapman to discuss our Projects for next semester and our experience at PC thus far.
Thursday (12/8) Tomie, Ilde and I worked with misroscopes to identify each of the bacteria. We checked if each one was Gram Positive or Gram Negative, then evaluated the shapes to determine the type of bacteria i.e. Spirilla, Cocci, Bascillus. We were successful in identifying most as either Staph or other type of Bascillus (I can't consult my notebook, which is at PC this very moment missing me). But there were some we couldn't i.d., even after consulting Rick and holding him captive for over an hour, and we weren't comfortable labeling them.
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