For preparation of FRASER broth, two different supplements are needed: FRASER Listeria Selective Supplement and FRASER Listeria Ammonium Iron (III) Supplement. The ammonium iron (III) citrate promotes the growth of the Listeria spp., and together with esculin (a component of the FRASER broth base), permits the β-D-glucosidase detection in Listeria spp.

FRASER Listeria Ammonium iron (III) Supplement is an additive for the preparation of Half FRASER (Demi FRASER) Broth (Base) or FRASER Broth (Base) for the enrichment of Listeria spp.