ID#: 8173
Magnified 100x, this 1977 photograph depicted a Petri dish filled with trypticase soy agar medium, containing 5% defibrinated sheep's blood. After having been inoculated by streaking the surface with Group A Streptococcus pyogenes (GAS) bacteria, the dish was incubated in a carbon dioxide enriched atmosphere at 35oC for 24 hours. The characteristic color changes, including a light colored halo surrounding each colony, indicated that these bacteria were beta-hemolytic in nature.
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Content Provider(s): CDC/ Richard R. Facklam, Ph.D.
Creation Date: 1977
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.