GRAM STAIN

A Gram stain is a test that checks for bacteria at the site of a suspected infection such as the throat, lungs, genitals, or skin wounds. Gram stains may also be used to check for bacteria in certain body fluids, such as blood or urine._x000D_
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There are two main categories of bacterial infections: Gram-positive and Gram-negative. The categories are diagnosed based on how the bacteria react to the Gram stain. A Gram stain is colored purple. When the stain combines with bacteria in a sample, the bacteria will either stay purple or turn pink or red. If the bacteria stay purple, they are Gram-positive. If the bacteria turns pink or red, they are Gram-negative.