What color do Gram-negative organisms typically appear after Gram staining?

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Multiple Choice

What color do Gram-negative organisms typically appear after Gram staining?

Explanation:
Differential staining separates bacteria by cell wall structure, using a primary dye and a counterstain. The Gram stain first colors all cells purple with crystal violet, but during the alcohol decolorization step, Gram-negative bacteria lose this dye because of their thin peptidoglycan layer and outer membrane. They then take up the pink counterstain, so they appear pink/red. Gram-positive organisms, with a thicker peptidoglycan layer, retain the purple dye. Green and clear aren’t typical final colors in this stain. So, Gram-negative organisms typically appear pink.

Differential staining separates bacteria by cell wall structure, using a primary dye and a counterstain. The Gram stain first colors all cells purple with crystal violet, but during the alcohol decolorization step, Gram-negative bacteria lose this dye because of their thin peptidoglycan layer and outer membrane. They then take up the pink counterstain, so they appear pink/red. Gram-positive organisms, with a thicker peptidoglycan layer, retain the purple dye. Green and clear aren’t typical final colors in this stain. So, Gram-negative organisms typically appear pink.

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