This image depicts the quantitative difference in hemolytic reactivity seen in a trypticase soy agar culture plate containing 5% sheep’s blood growing group-D Streptococci (left wedge), group-B Streptococci (middle wedge), and group-A Streptococci (right wedge) bacteria. This plate was grown under normal atmospheric conditions, at 35oC, for a periof of 18hrs. See PHIL 10862 for a magnified view of this culture plate, at approximately 10X.
It is important to note that the group-B Strep (GBS) center wedge, produced a hemolytic reaction that was less than the reaction produced by the group-A Strep (GAS) in the right wedge of bacterial growth. Hemolysis is one of the traits that is used to help identify the bacteria. Hemolysis is the destruction of the red blood cells suspended in the agar medium.