Eosin Methylene Blue Agar is a both selective and differential culture medium. It is selective culture medium for gram-negative bacteria (selects against gram positive bacteria) and is commonly used for the isolation and differentiation of coliforms and fecal coliforms.
Thus, the medium is considered differential with respect to lactose fermentation. MacConkey agar is similar to EMB agar in that it is also selective for Gram-negative species and differential with respect to lactose fermentation. MacConkey agar is used for the detection of coliforms and enteric pathogens based on their ability to ferment lactose.
Hektoen enteric agar is a selective as well as differential media for the isolation and differentiation of enteric pathogens from clinical specimens. The presence of the bile salts and dyes inhibit most gram-positive organisms allowing only gram-negative rods to grow on HE agar.
MacConkey agar is used for the isolation of gram-negative enteric bacteria and the differentiation of lactose fermenting from lactose non-fermenting gram-negative bacteria. It has also become common to use the media to differentiate bacteria by their abilities to ferment sugars other than lactose.
Differential media typically display some type color change in the presence of certain bacteria. Blood Agar (BAP) is another type of differential medium. BAP is rich in nutrients and contains sheep blood. It is not selective, and will grow many different types of microbes. Blood agar medium is, however, differential.
Composition of Triple Sugar Iron Agar (TSI) Lactose, Sucrose and Glucose in the concentration of 10:10:1 (i.e. 10 part Lactose (1%), 10 part Sucrose (1%) and 1 part Glucose (0.1%)). TSI is similar to Kligler’s iron agar (KIA), except that Kligler’s iron agar contains only two carbohydrates: glucose (0.1%) and lactose (1%).
Trypticase soy agar or tryptone soya agar (TSA) and Trypticase soy broth or tryptone soya broth (TSB) with agar are growth media for the culturing of bacteria. They are general-purpose, nonselective media providing enough nutrients to allow for a wide variety of microorganisms to grow.