A student investigates the concentration of viable bacteria in a stock culture of Escherichia coli using a serial dilution technique. They set up the dilution series and plate a sample onto nutrient agar as shown in the diagram below.
Following incubation, the student counts 144 separate colonies on the agar plate. Assuming each colony grew from a single viable bacterial cell, what is the concentration of viable bacteria in the original stock culture in cells/cm3\text{cells/cm}^3cells/cm3?
1.44×106 cells/cm31.44 \times 10^6\text{ cells/cm}^31.44×106 cells/cm3
7.2×105 cells/cm37.2 \times 10^5\text{ cells/cm}^37.2×105 cells/cm3
7.2×106 cells/cm37.2 \times 10^6\text{ cells/cm}^37.2×106 cells/cm3
2.88×105 cells/cm32.88 \times 10^5\text{ cells/cm}^32.88×105 cells/cm3
