Mueller Hinton Agar ( M173 )
Intended use
Recommended for determination of susceptibility of microorganisms to antimicrobial agents isolated from clinical samples.
Composition**
Ingredients g / L
HM infusion solids B # (from 300g) 2.000
Acicase ## 17.500
Starch 1.500
Agar 17.000
Final pH ( at 25°C) 7.3±0.1
**Formula adjusted, standardized to suit performance parameters
# – Equivalent to Beef heart infusion
## – Equivalent to Casein acid hydrolysate
Directions
Suspend 38.0 grams in 1000 ml purified/ distilled water. Heat to boiling to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C. Mix well and pour into sterile Petri plates. Note: The performance of this batch has been tested and standardised as per the current CLSI (formerly, NCCLS) document M6-protocols for Evaluating Dehydrated Mueller Hinton Agar.
Quality Control
Appearance
Cream to yellow homogeneous free flowing powder
Gelling
Firm, comparable with 1.7% agar gel.
Colour and Clarity of prepared medium
Light amber coloured clear to slightly opalescent gel froms in Petri plates
Reaction
Reaction of 3.8% w/v aqueous solution at 25°C. pH : 7.3±0.1
pH
7.20-7.40
Cultural Response
Antibiotic susceptibility tests are performed in accordance with, and meet the acceptance limits of the current ISO/TS16782 (15). Performance of the medium is checked in accordance with the CLSI/ EUCAST guidelines.
Storage and Shelf Life
Store between 10-30°C in a tightly closed container and the prepared medium at 20-30°C. Use before expiry date on the label.