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This photograph depicts the colonies of Gram-negative, Proteus mirabilis bacteria, grown on a xylose-lysine-deoxycholate (XLD) agar plate. Xylose Lyseine (XL) agar is used when trying to culture and isolate Gram-negative enteric bacilli. When XL agar is supplemented with sodium thiosulfate, ferric ammonium citrate, and sodium deoxycholate, it is then termed XLD agar, and is then an even more selective medium than XL alone. The presence of any black color indicates the deposition of hydrogen sulfide, (H2S) under alkaline conditions.
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Content Providers(s):CDC
Creation Date:1976
Photo Credit:
CDC Organization
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Copyright Restrictions:None - This image is in the public domain and thus free of any copyright restrictions. As a matter of courtesy we request that the content provider be credited and notified in any public or private usage of this image.