OD calibration

Aim

We have calibrated the absorbance at 600nm (O.D.600) with the colony forming units. This allows us to approximate our absorbance data into a cell count number. We can now normalise fluorescence data to obtain the fluorescence produced per cell.

Experimental procedure

Cells were grown overnight in incubator at 225rpm shaking.
In the morning, the OD was measured using a multi-well plate reader.

The cell solution was then diluted to form a range of OD values.
Each OD solution was diluted down and plated on agar plates overnight.
The colonies were then counted the next morning.

We performed the experiment and further reruns with 2-3 repeats per OD value and for 2 different dilutions.

Results

Conclusions

We are now able to correlate the OD measured on the multiwell plate reader to the actual number of colony forming units. This allows us to normalise fluorescence data.