Agarobiose, the repeating unit of Agarose, is a disaccharide composed of D-galactose and 3,6-anhydro-L-galactose
is the repeating unit of the agarose polymer
It's a differential agar used to differentiate between lactose fermenters and non-lactose fermenteing bacteria. Chemical composition of Mac Conkey agar Peptone 20.0g Trehalose 10.0g Bile salts(Difco) 1.5g Sodium Cloride 5.0 Neutral Red 0.05g Crystal Violet 0.001 Agar 15.0g Distelled water 1.0 liter pH: 7.4±0.2 (25 °C)