DEY ENGLEY NEUTRALISING BROTH

Dey-Engley Neutralizing Broth is used for the neutralization and testing of antiseptics and disinfectants, especially in environmental sampling where residual chemical activity may interfere with the recovery of microorganisms. It is formulated to neutralize a wide range of antimicrobial agents including quaternary ammonium compounds, phenolics, iodine and chlorine compounds, mercurials, formaldehyde and glutaraldehyde.
The composition includes tryptone which provides nitrogen, carbon, amino acids, vitamins and other nutrients. Dextrose provides energy and yeast extract contains B-complex vitamins. Different neutralizing agents target different chemical residues: sodium bisulfite neutralizes aldehydes, sodium thioglycollate acts on mercurials, sodium thiosulfate neutralizes iodine and chlorine, lecithin neutralizes quaternary ammonium compounds, and polysorbate 80 neutralizes substituted phenolics.
Bromocresol purple is an indicator of dextrose metabolism. Dextrose-fermenting organisms show a change of color from purple to yellow. Since the high lecithin concentration can make turbidity difficult to interpret, growth of non-fermenters such as Pseudomonas species may be indicated by pellicle formation on the broth surface.

Neutralizes a broad range of antiseptics and disinfectants, enabling effective evaluation of their bactericidal activity during environmental testing.