Gram Stain Procedure and Techniques

The video tutorial explains the Gram stain procedure, highlighting variations and following the American Society of Microbiology's guidelines. It details each step: applying Crystal Violet, iodine, decolorizer, and saffron, followed by rinsing and drying the slide. Finally, it describes viewing the stained slide under a microscope, noting that Gram-positive cells appear purple and Gram-negative cells appear pink.

What is the primary purpose of the Gram stain procedure?

• To determine the motility of bacteria

• To measure the size of bacteria

• To differentiate between Gram-positive and Gram-negative bacteria

• To identify the shape of bacteria

Which reagent is used first in the Gram stain procedure?

• Decolorizer

• Safranin

• Gram's iodine

• Crystal Violet

How long should the slide be flooded with Crystal Violet?

• 20 seconds

• 15 seconds

• 5 seconds

• 10 seconds

What is the role of Gram's iodine in the staining process?

• To act as a mordant

• To stain the bacteria pink

• To fix the bacteria to the slide

• To decolorize the slide

What should be done immediately after applying the decolorizer?

• Flood the slide with safranin

• View under a microscope

• Rinse the slide with water

• Blot the slide with paper

Which stain is used last in the Gram stain procedure?

• Safranin

• Decolorizer

• Gram's iodine

• Crystal Violet

What is the purpose of using bibulous paper in the procedure?

• To enhance the color

• To dry the slide

• To remove excess stain

• To fix the bacteria

What is the magnification used to initially locate the cells on the slide?

• 100x

• 40x

• 400x

• 10x

What is added to the slide before viewing under the 100x oil objective?

• Immersion oil

• Safranin

• Water

• Crystal Violet

What color do Gram-negative cells appear after the staining process?

• Green

• Blue

• Pink

• Purple