Team:WashU StLouis/Interlab

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We did the interlab study. ✅

WashU iGEM Interlab Study Results

This summer, in addition to our work on our iGEM project, we participated in the annual interlab study, a study whose goal is to compare measurements from different labs across the world. This year, the interlab study could be broken down to three basic parts:

  1. Calibrating the OD600 by measuring with LUDOX
  2. Finding a fluorescence standard curve with FITC
  3. Measuring cell output fluorescence with 5 test devices

Below are our results for each part of the interlab study. At the end, we propose some improvements to the interlab study protocol.

Part 1

OD600 correction using LUDOX **Reference OD600 = 0.01475

Replicate 1 Replicate 2 Replicate 3 Replicate 4 Average Corrected Correlation Factor
LUDOX 0.0504 0.0553 0.0483 0.0511 0.051275 0.00765 1.928104575
Water 0.0433 0.0418 0.0472 0.0422 0.043625 N/A N/A
Part 2

FITC Standard Curve

At this point in the interlab study, we encountered our first error. Our plate reader failed to measure fluorescence higher than 40,000 au. Therefore, we were unable to get results for highest five concentrations of FITC. See the end of this page to see our suggestions on avoiding this problem in the future.
Part 3

Cell fluorescence with 5 test plasmids

Graph of Fluorescence values

As seen in the graph above, fluorescence for all the devices increased as time went on, as expected. The negative control and device 3 both produced only small amounts of fluorescence.

WHAT WE WOULD IMPROVE:
  • Further specifics should be given for measuring the FITC standard curve. For example, the protocol says to measure for GFP. Instead, a specific wavelength should be given.
  • We are not sure if other teams had this issue, but we could not tell when the given FITC was properly resuspended. Due to a pipetting error, we lost our FITC and had to buy some from Thermo-Scientific. We believe that our store-bought FITC, which was not premeasured like the iGEM-supplied one, might have contributed to our wonky FITC curve. Having extra FITC would be helpful in case of an error.
  • Finally, we believe it is common practice to perform tests in triplicate, so we would recommend testing each colony in triplicate to get the best possible results.