Each sample is one lyophilized quantitative standard containing E. coli in the range 20200 CFU/100 mL or MPN/100 mL. Use with all SDWA quantitative methods. Each standard can be used for total coliform, fecal coliform, and E. coli. If determining MPN by SM 9221 or similar multiple tube techniques, use 078A, 595A, and 078AQR.