Used to make minute organisms visible, display their structure in the microscope, reveal their chemical nature and influence their growth and development
Used to show by special staining methods and reveal the physiochemical characteristics and differences among bacteria that aid in their description and classification, two or more dyes employed
Gram's rule: All cocci are Gram (+) except for Neisseria, Moraxella, Veillonella, Branhamella. All bacilli are Gram (-) except for Mycobacterium, Corynebacterium, Bacillus, Erysipelothrix, Lactobacillus, Listeria & Nocardia. All spirals are Gram (-)
Acid fast bacteria are those organisms which are not decolorized by acid once they have been stained, due to high content of lipodal substance known as mycolic acid or hydroxymethoxyl acids
Differentiates acid-fast from non-acid fast organisms, no heating or steaming required but the concentration of phenol is increased to increase penetration on the bacteria's cell wall