Mueller Hinton Broth Himedia M391-500g Mueller Hinton Broth is recommended to determine the susceptibility of bacteria to sulphonamides by the tube dilution method. Also used for primary isolation of gonococci and meningococci. Composition** Ingredients Gms / Litre Beef, infusion from 300.000 Casein acid hydrolysate 17.500 Starch 1.500 Final pH ( at 25°C) 7.3±0.1 **Formula adjusted, standardized to suit performance parameters Directions Suspend 21 grams in 1000 ml distilled water. Heat to boiling to dissolve the medium completely. Mix well and dispense into tubes as desired. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Principle And Interpretation The Mueller Hinton formulation was originally developed as a simple, transparent agar medium for the cultivation of pathogenic Neisseria species (2). Other media were subsequently developed that replaced the use of Mueller Hinton Agar for the cultivation of pathogenic Neisseria species, but it became widely used in the determination of sulfonamide resistance of gonococci and other organisms. Mueller Hinton Broth is recommended for dilution antimicrobial susceptibility testing of all species of most commonly encountered aerobic and facultatively anaerobic bacteria (3, 1). Beef infusion and casein acid hydrolysate provide nitrogenous compounds, carbon, sulphur and other essential nutrients. Starch acts as a protective colloid against toxic substances present in the medium. Starch hydrolysis yields dextrose, which serves as a source of energy. These ingredients are selected for low thymine and thymidine content as determined by MIC values for Enterococcus faecalis with sulfamethoxazoletrimethoprim (SXT). Calcium and magnesium ion concentrations are adjusted to provide the amounts recommended by CLSI to give the correct MIC values with aminoglycosides and Pseudomonasaeruginosa (3).