Egg Yolk Tellurite Enrichment , gamma irradiated BD Difco™ 6 x 10 ml. Fraser Broth Supplement Contains 0.05 g ferric ammonium citrate. The medium is used in the rapid detection ofListeria from food and environmental samples. Use with: Fraser Broth Base (Cat. No. 211767and 211766) and Demi-Fraser Broth Base (Cat. Nos. 265310 and 265320).