A broth culture medium intended to be used to promote the selective growth of a microbial species with specific characteristics (e.g., antibiotic resistance, ability to utilize, synthesize specific metabolites) and/or distinguish between microbial species growing in the same medium. It typically contains substances to inhibit the growth of commensal or contaminating microorganisms (e.g., antimicrobials, dyes, salts) and/or dyes or chemical indicators for differentiation.