Flashcards on Gram staining
Gram Staining: A Comprehensive Guide for Students
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Gram Staining
63 cards
Card 1
Question: What is Gram staining used for in microbiology?
Answer: Classifying bacteria into two major groups: Gram-positive and Gram-negative.
Card 2
Question: Who developed the Gram staining procedure and when?
Answer: The Danish bacteriologist Hans Christian Gram in 1884.
Card 3
Question: What is the basis for Gram staining's differential classification of bacteria?
Answer: Fundamental differences in the structure of bacterial cell walls, which dictate how they retain certain dyes.
Card 4
Question: Why is distinguishing between Gram-positive and Gram-negative bacteria crucial?
Answer: For preliminary bacterial identification, guiding clinical diagnosis, and informing the selection of appropriate antibiotic treatments.
Card 5
Question: What is the core principle of Gram staining?
Answer: Differential retention of a primary stain (crystal violet) by bacteria with varying cell wall compositions.
Card 6
Question: Describe the cell wall of Gram-positive bacteria.
Answer: A thick peptidoglycan layer and lack an outer lipid membrane.
Card 7
Question: Describe the cell wall of Gram-negative bacteria.
Answer: A thin peptidoglycan layer situated between an inner cytoplasmic membrane and an outer lipid membrane.
Card 8
Question: What color do Gram-positive bacteria appear under a light microscope after Gram staining?
Answer: Purple
Card 9
Question: What color do Gram-negative bacteria appear under a light microscope after Gram staining?
Answer: Pink or red
Card 10
Question: What is the most prominent feature of a Gram-positive cell wall?
Answer: A thick, multilayered peptidoglycan (murein) network, typically 20-80 nanometers (nm) thick.