The InterLab project is designed to help bring synthetic biology one step closer to standard engineering. By having a large number of vastly different iGEM labs around the world complete the calibrations and protocols, a standard set of basic measurements can be produced. These standard measurements will help to provide teams with data to compare against their own experiments in the future.
We completed three calibrations before completing measurements of competent cells. The first calibration established an OD600 Reference point. The second calibration used microspheres to mimic the properties of cells suspended in solution. This allowed for the creation of a standard curve of absorbance values based on known concentrations of microsphere solutions. This provides a reference against which solutions of actual cells could be measured for their concentration. The final calibration used fluorescein to create a standard curve of fluorescence values at different concentrations.
After the calibrations were completed, E. coli, of the strain DH5-α, was transformed with the devices in the table below into pSB1C3. These cells were then grown in cultures and run through a series of dilutions. Samples from each colony was measured for Absorbance600 and Fluorescence. Then, this data was compared to the standard calibrations curves.
Test Device 1
Test Device 2
Test Device 3
Test Device 4
Test Device 5
Test Device 6
Finally, in order to validate our OD600 results, we compared them to data produced from colony forming units. The cultures were taken, diluted further, and grown on plates. The plates were incubated and the colonies were counted. A correlation was then produced between the concentration of solution to the number of colonies on each plate.
The InterLab is an outstanding collaboration effort, and efforts like these are what is turning genetic engineering into a widely accessible tool to unlock all of its possibilities.