MIC 206 FINAL| 260 questions| with complete solutions

what is a simple stain and what does it allow for correct answer: A basic stain that is rinsed with water that allows one to identify cell morphology (shape) and arrangement three cell shapes correct answer: bacillus, cocci, spirillum what do stains contain that allow staining to occur correct answer: they contain chromophores, color bearing ions by adding colored compounds in staining, we add ___ for visibility of cells correct answer: contrast charge of bacterial cells correct answer: negative examples of basic stains correct answer: methylene blue, safranin, crystal violet what type of stain needs to be used for bacteria, and why correct answer: basic stains, as the nucleic acids of the bacteria attract the positive ions type of ions that basic stains have correct answer: cations (+ charges) example of an acidic stain correct answer: nigrosin type of ions that acidic stains have correct answer: anions (- charges) what type of stain stains backgrounds correct answer: acidic stains since bacteria are attracted to the cations on negative stains how to perform a smear prep correct answer: 1. draw circle about size of quarter on bottom of slide 2a. if from broth, take 1-2 loops of bacteria 2b. if from plate, use loop of water, then small amount from side of a colony 3. make sure to smear it around the slide 4. allow it to air dry 5. heat fix by holding the slide in front of the bacticinerator (with bacteria facing away) for about 5 seconds 6. floor slide with stain 7. wash slide with water 8. use bibulous paper and gently blot dry 9. record images under 1000x magnification with oil