The Alethia Group B Streptococcus (GBS) assay, performed on the Alethia Incubator/Reader, is a qualitative in vitro diagnostic for the detection of Streptococcus agalactiae in enriched cultures obtained from vaginal/rectal swab specimens from antepartum women. Enriched cultures are obtained by 18-24 hour incubation of vaginal/rectal swab specimens in selective broth medium, either Lim Broth, TransVag Broth or Carrot Broth