After Gram staining, what color do Gram-negative bacteria appear?

Unlock all features

Unlock your full potential with Examzify Plus. Access the complete question bank, personalized progress tracking, and an ad-free experience.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Prepare for the WGU NURS1010 Microbiology Exam with engaging study materials, flashcards, and multiple choice questions. Enhance your understanding with detailed explanations and insights. Get exam-ready today!

Multiple Choice

After Gram staining, what color do Gram-negative bacteria appear?

Explanation:
Gram staining differentiates bacteria by cell wall structure. After the crystal violet and iodine steps, a decolorizing rinse with alcohol dissolves the outer membrane and washes away the crystal violet-iodine complex from the thinner peptididoglycan of Gram-negative cells. When the counterstain is applied, these cells take up the pink dye (safranin) and appear pink under the microscope. In contrast, Gram-positive bacteria retain the purple crystal violet because their thick peptidoglycan layer holds onto the dye. Therefore, Gram-negative bacteria appear pink.

Gram staining differentiates bacteria by cell wall structure. After the crystal violet and iodine steps, a decolorizing rinse with alcohol dissolves the outer membrane and washes away the crystal violet-iodine complex from the thinner peptididoglycan of Gram-negative cells. When the counterstain is applied, these cells take up the pink dye (safranin) and appear pink under the microscope. In contrast, Gram-positive bacteria retain the purple crystal violet because their thick peptidoglycan layer holds onto the dye. Therefore, Gram-negative bacteria appear pink.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy