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Medical Term:

Gram stain

Pronunciation: gram


a method for differential staining of bacteria; smears are fixed by flaming or methanol, stained in a solution of crystal violet, treated with iodine solution, rinsed, decolorized, and then counterstained with safranin O; gram-positive organisms stain purple-black and gram-negative organisms stain pink; useful in bacterial taxonomy and identification, and also in indicating fundamental differences in cell wall structure.

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