Hi-Sensitivityâ„¢ Test Agar is recommended for antimicrobial susceptibility tests. The thiamine and thymidine content is very low which makes media suitable for testing antimicrobial activity of sulfonamide. The media is a semidefined medium in which the mineral contents have been stabilized to give reproducible results. Supplemental nutrients can be added to Hi-Sensitivity Test Agar to improve the growth of these organisms.