Description
3/pack
DESCRIPTION
LISTERIA DEMI FRASER BROTH – BAG is a ready to use liquid medium in bag for enrichment of Listeria monocytogenes in foods according to ISO 11290. The bags can be placed on special supports, connected to sterile tubes with the aid of specific joints and used with diluters, peristaltic pumps o, simply, you can bring the liquid to fall.
METHOD PRINCIPLE
LISTERIA DEMI FRASER BROTH prepared according to the formulation described by Fraser, is a modification of UVM enrichment broth. Tryptone, peptone and beef and yeast extracts provide nitrogen, carbon, sulphur and vitamins. Lithium chloride and sodium chloride maintain the osmotic balance of the medium. Potassium phosphate monobasic and sodium phosphate bibasic are buffers. High sodium chloride concentration is a selective agent. The presence of Listeria spp. is indicated by hydrolysis of aesculin to produce esculetin which reacts with ferric ions causing the blackening of the broth.