File:EvaporationEffectonA600.png

This experiment was designed to assess the impact of evaporation upon the absorbance reading at 600nm of a culture sample in the Victor3 plate reader. A master culture of both pSB4K5-P20060 in MG1655 and pSB4K5-P20060.E0433 in TOP10 was grown. For each construct, 50μL of culture was aliquoted into each well of 3 rows in a 96 well plate. Two rows were left empty. To each well, between 0 and 100 μL of H₂O was added to the sample and the absorbance at 600nm was measured. This setup was intended to mimic the situation in which there is a sample with a constant amount of absorbing material (i.e. cells) in the well, and there is evaporation of water over time from the well thereby changing both the concentration of material and volume of liquid (path length) in the well. Thus, the variability in absorbance due to different amounts of H₂O added should reflect the variability in absorbance due to evaporation in experiments. This graph also shows 3 replicates of each combination of 50 μL culture + X μL of H₂O to provide an indication of the variability between identical samples.