Another differential stain technique is the acid

Another differential stain technique is the acid - Other...

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Another differential stain technique is the  acid-fast technique.  This technique  differentiates species of  Mycobacterium  from other bacteria. Heat or a lipid solvent is  used to carry the first stain, carbolfuchsin, into the cells. Then the cells are washed with  a dilute acid-alcohol solution.  Mycobacterium  species resist the effect of the acid-alcohol  and retain the carbolfuchsin stain (bright red). Other bacteria lose the stain and take on  the subsequent methylene blue stain (blue). Thus, the acid-fast bacteria appear bright  red, while the nonacid-fast bacteria appear blue when observed under oil-immersion  microscopy. 
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Unformatted text preview: Other stain techniques seek to identify various bacterial structures of importance. For instance, a special stain technique highlights the flagella of bacteria by coating the flagella with dyes or metals to increase their width. Flagella so stained can then be observed. A special stain technique is used to examine bacterial spores. Malachite green is used with heat to force the stain into the cells and give them color. A counterstain, safranin, is then used to give color to the nonsporeforming bacteria. At the end of the procedure, spores stain green and other cells stain red....
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