LB Nutrient Agar is a nutrient-rich medium initially developed for the growth and maintenance of Escherichia coli strains. It is currently the most widely used medium for bacterial growth. Each liter of LB Nutrient Agar contains: 10.0 g of tryptone, 5.0 g of yeast extract, 10.0 g of sodium chloride, and 15.0 g of agar.