Hektoen (gélose)
The gélose Hektoen is a Culture medium being used to insulate the Salmonella , Shigella , Yersinia .
Composition
- Proteose - Peptone: ............................ 12,0 G - extract of Yeast: growth factor ............................ 3,0 G - Lactose criterion of differentiation ...................................... 12,0 G - Saccharose criterion of differentiation ................................... 12,0 G - Salicin criterion of differentiation ...................................... 2,0 G - iron III and revealing ammonium citrate of H2S .............. 1,5 G - biliary Salts inhibiting ................................ 9,0 G - Fuchsine acid inhibiter ................................ 0,1 G - Blue of indicating bromothymol of pH ........................... 0,065 G - Sodium chloride maintenance of the osmotic pressure ............................ 5,0 G - precursory sodium thiosulfate of H2S ......................... 5,0 -] ............................. 13,0 G :: pH = 7,5
Preparation
75 G per liter. NOT AUTOCLAVER.
Reading
The colonies are normally colonies of bacillus S negative Gram. The colonies in black center are H2S +. The blue or green colonies do not use any the Glucide S of the medium. They are thus saccharose and salicin and lactose negative. The blue color can be due to the use of citrate. The yellow colonies use one or more glucids. They are thus saccharose and/or lactose and/or salicin positive. A biliary salt precipitate can appear for the acidifying stocks.
See too
- Culture medium
- Culture media (list)