Description
Mueller Hinton Agar | DM170
A standardised medium for susceptibility testing.
In 1941 Mueller and Hinton described a medium for the isolation of gonococci and meningococci, which was later used for
susceptibility testing of gonococci by Goodale.¨ Since that time, Mueller Hinton medium has become generally accepted in
the U.S.A. as a routine susceptibility test medium. Bauer et al. (1966) described its use in their standardised susceptibility test method which has been adopted by the Food and Drug Administration U.S.A. (1972). The International Collaborative
Study Group (1971)5 also recommended this medium with 5% defibrinated blood, for the international standard disc susceptibility test method. Mast Mueller Hinton Agar has been designed to conform to these recommendations and is a highly nutritious medium, which with added blood (5%) is suitable for the growth of most fastidious organisms. It is low in sulphonamide and tetracycline antagonists giving clear zones with these drugs. The agar used has been modified by ion exchange to minimise the variable effects that batches of agar may have on the diffusibility and activity of certain drugs.
Technical Formula*
Directions
1. Suspend by swirling 38g of powder in 1 litre or the contents of the sachet in the stated volume of distilled or deionised water.
2. Autoclave at 121°C (15p.s.i.) for 15 minutes. DO NOT OVERHEAT. Overheating hydrolyses the starch. If required, add 5%
defibrinated blood on cooling to 50°C.
3. Allow to cool before distribution.