InterLab Study

Measurement techniques are essential for quantifying and communicating results that are meaningful in comparison to a standard. The iGEM Measurement Committee aims to develop robust measurement procedures for enhancing the quantification and reproducibility of results through the InterLab Study. These results can then be used to reliably characterize biological constructs.

For the InterLab Study this year, participating iGEM teams follow a standardized protocol for measuring green fluorescent protein (GFP) using E. coli DH5 cells and a plate reader. Fluorescence data is typically difficult to compare between laboratories because fluorescent measurements are not reported in the same units or the methods of data processing are different. The goal of the InterLab Study is to determine absolute units for measuring GFP that are comparable despite the type of plate reader used to make the measurements.

More details about the standardized protocol we used for the study can be found here.

Below you will find our data we collected for the InterLab Study using BioTek Synergy 4 plate reader.

The InterLab Study can be broken down into two parts: plate reader calibration and cell measurement. Below you will find the data we collected for the InterLab Study using the BioTek Synergy 4 plate reader.

— Calibration —

OD600 Reference Point
The OD600 reference point can be used along with standard LUDOX Abs600 measurements to determine a correction factor that can convert our absorbance measurements into standard optical density measurements.

To obtain the correction factor we prepared a reference OD600 with a spectrophotometer and collect absorbance data with a plate reader using LUDOX-S40 and DI water. The correction factor is calculated by dividing the reference OD600 over the Abs600. Our results are shown below.

Fluorescein Fluorescence Standard Curve
We then prepared a series of fluorescein in 4 replicates to measure fluorescence with the plate reader.