Dey-Engley neutralising broth is used in disinfectant testing where neutralisation of the antiseptics and disinfectants is important for determining bactericidal activity.

Components include casein enzymatic hydrolysate (5,00), yeast extract (2,50), dextrose (10,0), sodium thiosulphate (6,00), sodium thioglycollate (1,00), sodium bisulphite (2,50), lecithin (7,00), polysorbate (80 5,00) and bromocresol purple (0,02).