First time I did the experiments the CFU results showed that

**0.3 OD = 2.07 x 10**

^{8}cells/ml.After some weeks I did the same experiment and the CFU results are showed to me that

**0.3 OD = 1.41 x 10**

^{9 }cells/ml.I am not sure why I am getting that different values of CFU for same OD?

Any help will be highly appreciated. Thanks