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Always remove the right eyepiece without the eyepiece

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Always remove the Right Eyepiece (without the Eyepiece Reticle). Your Zeiss Microscope is as Air-Tight as a 1968 Volkswagen. So when you pull-out an Eyepiece, you ʼ re creating a Partial Vacuum within the Microscope that would dislodge the Ocular Micrometer in the Left Eyepeice (which is why you should remove the Right Eyepeice). 14. Adjust the Condenser Diaphragm such that 3/4 of the Field of View is filled with Light (i.e. close-down the Condenser Diaphragm by about 1/4). If you ʼ re looking West while skiing at Tahoe, you ʼ ll probably raise your Hand above your Eyes to shield them from Glare. We ʼ re doing the same thing here by closing down the Cone of Light a bit so those Light Rays at the Edges and outside of the Cone of Light (the ones producing “Glare”) are blocked. You centered the Field Diaphragm in Step 11. Now you ʼ re adjusting the Condenser Diaphragm. Don ʼ t worry if this guy isn ʼ t centered. 15. Replace the Right Eyepiece. 16. Use the Mechanical Stage Controls to move the “P” back into Place. If the P is still in focus, you did it! If the P is not in Focus, you screwed-up! The most common Way to screw-up is to use the Fine and Course Focus Knobs to focus the Image of the Field Diaphragm. No! Bad Student! B ad ! Always use the Condenser Focus Knob to focus the Image of the Field Diaphragm.
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Lab 3 Page 8 The Gram Stain (Atlas Figure 6-1, Page 45) Materials (per Student): • Slides • Loop • Bunsen Burners • Gram Stain Reagents (Crystal Violet, Iodine, Alcohol, Safranin) • DI Water Bottle (not your Bacdown Bottle) • The Bacterium to be Gram Stained • Gram Stain Controls (incredibly Optional): - Staphylococcus epidermidis is our Gram Positive Control. - E. coli is our Gram Negative Control. Fun With Stains Before you do your first Gram Stain you should do a brief Exercise that quite graphically shows what’s going-on during a Gram Stain: 1. Add a Drop of Crystal Violet to a clean Glass Slide. 2. Add a Drop of Iodine to the Crystal Violet on the Slide. You’ll see a metallic-looking Crystal Violet-Iodine Precipitate forming on the Slide, just like it forms inside the Bacterial Peptidoglycan Layer. 3. Add a Drop of Ethanol. Gadzooks! You will see the Crystal Violet- Iodine Precipitate dissolves. And Ethanol solubilizes the Crystal Violet-Iodine Precipitate in the Peptidoglycan Layer, too. Neat, huh? Gram Stain Procedure: 1. Make a Smear of the Bacterium you want to Gram Stain in the Center of a Slide (Use the Goldilocks Three Slide Method you learned last Week). You can also make Smears of your Controls on either Side of your Bacterium on this same Slide. But the Difficulty of properly destaining three Smears has proven to be such a Nuisance that most Students don ʼ t use our Controls. It ʼ s your Call. 2.
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Always remove the Right Eyepiece without the Eyepiece...

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