Strep B Carrot Broth™ One-Step is a selective and differential medium which is intended for the detection of Group B Streptococcus (GBS) from anovaginal specimen collected from pregnant women. The medium is used as an aid in the qualitative determination of GBS colonization in pregnant women. The color change reaction from white to orange is representative of a positive result for presence of GBS. The medium requires 24 hours of incubation but positive results can be interpreted and reported as early as 16 hours. Due to the properties of Strep B Carrot Broth™ One-Step, non-hemolytic GBS cannot be detected by the medium’s color change and requires subculture for identification. Any presumptive negative indicated by lack of color change at the end of the incubation period must be subcultured to a non-selective medium (e.g., Tryptic Soy Agar with 5% Sheep Blood) to confirm absence of GBS. Subculture must also be performed to recover isolates for conducting susceptibility testing as recommended for penicillin-allergic women.