Microbiology Staining Study Guide Test.

Microbiology Staining Study Guide Test. Gram stain - CORRECT ANSWER Positive differential stain, primary dye: crystal violet, mordant: iodine, decolorizer: acetone alcohol, counter stain: safranin, gram positive: purple, gram negative: pink. Simple stain - CORRECT ANSWER Positive stain methylene blue, blue cells, shape/arrangement apparent. Acid fast stain - CORRECT ANSWER Positive differential stain, primary dye: Carbol fuchsin, mordant: steam, decolorizer: acid alcohol, counter stain: methylene blue, acid fast: red/pink, non-acid fast: blue. Endospore stain - CORRECT ANSWER Positive differential stain, primary dye: malachite green, mordant: steam, decolorizer: dH2O, counter stain: safranin, endospores: green, vegetative cells: pink. Negative stain - CORRECT ANSWER Negative stain (acidic/anionic dyes), nigrosin, gray cells on a dark background (shape and size apparent). Simple stain - CORRECT ANSWER Single staining reagent is used to color the bacterial smear. Simple stain - CORRECT ANSWER Common dyes are crystal violet and methylene blue. Electrical charge - CORRECT ANSWER All bacterial cells are slightly negatively charged because of the large numbers of phospholipids that compose the cell membranes. This negative charge is attracted to the positively charged chromosomes or basic dyes. Simple stain procedure - CORRECT ANSWER 1. Disinfect bench top, gather materials. 2. Prepare smear. 3. After smear has air dried, heat fix. 4. Flood smear with methylene blue and allow to stand 1 minute. 5. Wash gently with distilled water. 6. Place slide within bibulous paper or paper towel and gently blot dry.