Haemophilus influenzae cultivated on chocolate agar. Cultivation 24 hours, 37 °C in an aerobic atmosphere enriched with 5% carbon dioxide. Isolated from a patient with pneumonia.

Haemophilus influenzae grows rapidly on chocolate agar, producing 1- to 3-mm translucent colonies after overnight incubation under microaerophilic (aerobic atmosphere enriched with 5-10% of carbon dioxide) or anaerobic conditions.

Encapsulated strains may produce larger colonies with a glistening mucoid quality.