Turbidity Measurements
You often need quicker results to determine the number of bacteria in a sample. If you have a culture growing
in log phase you can use the plot of broth turbidity with a known viable colony count. You can use this graph
to determine the number of viable bacteria in another culture grown under the same conditions that you
created your graph with. You can plot the optical density on the y-axis against the concentration on the log xaxis.
Any point along the straight portion of the line can be used to calculate the viable cell count from that
dilution factor. This is extremely helpful in the biotech industry where actively grown cultures are routinely
used.