How do you perform the E. coli test?

𝐒𝐚𝐦𝐩𝐥𝐞 𝐏𝐫𝐞𝐩𝐚𝐫𝐚𝐭𝐢𝐨𝐧
Enrich Sample B in Soybean Casein Digest Medium (SCDM) by incubating at 30-35°C for 24 hours.
𝐈𝐧𝐨𝐜𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐢𝐧 𝐌𝐂𝐁
After enrichment, add 1 ml of Sample B to Modified Brilliant Green Bile Broth (MCB).
Incubate this mixture at 42-44°C for 48 hours.
𝐏𝐥𝐚𝐭𝐢𝐧𝐠 𝐚𝐧𝐝 𝐈𝐧𝐜𝐮𝐛𝐚𝐭𝐢𝐨𝐧
After incubation in MCB, streak the sample onto MacConkey Agar (MCA) plate.
Incubate the MCA plate at 30-35°C for 72 hours.
𝐑𝐞𝐬𝐮𝐥𝐭 𝐚𝐧𝐝 𝐈𝐧𝐭𝐞𝐫𝐩𝐫𝐞𝐭𝐚𝐭𝐢𝐨𝐧
Observe for brick-red colonies on the MCA plate, which indicate the presence of E. coli (due to lactose fermentation).