Brain Heart Infusion (BHI) Agar is a general purpose medium suitable for the cultivation of a wide variety of organism types, including bacteria, yeasts and molds. The plates are deep-filled to reduce the effects of drying during prolonged incubation.

In the early years of bacteriology, meat infusions were utilized as the growth-supporting components in a large number of culture media. Although they were cumbersome to prepare, lacked consistency from batch to batch and were undefined as to their nutritive content, they enabled the cultivation of microorganisms in both solid and liquid media. As the state-of-the-art in enzymology and chemistry advanced, methods were developed for the preparation of peptones which were the result of enzymatic or acid hydrolysis of animal tissues or products and vegetable substances. These peptones currently are the major nutritional additives to culture media formulations, but infusions are still utilized in specific media.

Brain Heart Infusion Agar is one formulation in which meat infusion is used, although, unlike in the earlier days, the infusion components are solids resulting from the drying of the liquid infusion material rather than the liquid components themselves. Two peptones are also included as sources of nutrients.

This medium has proven to be effective in the cultivation of a wide variety of microorganisms, including many types of pathogens. It has served as the base medium for new culture media formulations when supplemented with sheep blood, cycloheximide, chloramphenicol, and/or gentamicin. BHI Agar currently is recommended as a general medium for aerobic bacteriology and for the primary recovery of fungi from clinical specimens.^1,2