LACTOSE BROTH FOR ISOLATING BACTERIUM COLI FROM WATER.

These authors suggest simplification of the technic by reducing the lactose content by addition of gentian violet, also Pasteurization in place of autoclaving. The announced value of gentian violet for preliminary enrichment of colon cultures is sustained, with cleaner plates and readier identification of colonies. Gentian violet has also advantages in ensuring keeping qualities in the broth.