Microbiology Lab Exam 1

Microbiology Lab Exam 1 Which dyes are used in a Simple Stain? Methylene Blue, Gram's Crystal Violet, or Gram's Safranin (All primary dyes) What are the steps to perform a smear from broth medium or solid medium 1. Drop a couple drops of water on clean slide (if using solid medium) 2. Aseptically transfer with inoculation loop or needle and mix bacteria and spread out water. 3. Allow smear to air dry 4. Heat fix sample to slide 5. Allow to cool and then proceed with stain protocol What are the steps of a simple stain 1. Perform a bacterial smear 2. Saturate smear with basic dye for approx. 1 minute with blue, crystal violet, or safranin 3. Rinse slide gently with water 4. Carefully blot with bibulous paper 5. Observe under microscope with proper technique. Which dyes are used in a Negative Stain? Nigrosin (primary dye) What are the steps of a negative stain? 1. Place a single drop of nigrosine on a clean microscope slide, adjacent to frosted edge 2. Using flame looped sterile technique, remove some organism from tube or plate, and mix it into nigrosin droplet. 3. Place the end of another clean microscope slide at an angle to the end of slide containing organism and spread drop out onto film.