Tampons shouldn't be worn overnight because... 1  Tampons need to be changed every 4-6 hours and many people sleep longer than this - changing often is important as tampons allow bacterial growth while preventing vaginal cleaning so the longer a tampon is worn the more bacteria can multiply within the vagina.
MacConkey agar is a selective medium containing bile salts and crystal violet that inhibits the growth of Gram-positive bacteria while allowing for the growth of Gram-negative bacteria.MacConkey agar is often used when investigating and culturing fecal bacteria.he MacConkey agar we talked about as an example of a selective media is also a differential media. In addition to the selective bile salts and crystal violet, MacConkey agar contains a pH indicator and the sugar lactose.
10 slides per box. A more selective modification of MacConkey medium which is suitable for the detection and enumeration of coliform organisms and also for the detection and isolation of Salmonella and Shigella species occurring in pathological and food specimens.ue to the inclusion of a specially prepared fraction of bile salts in addition to crystal violet, the medium gives improved differentiation between coliforms and non-lactose fermenting organisms whilst Gram-positive cocci are completely inhibited.