Introduction

Reliable and repeatable measurement is a key component to all engineering disciplines. The same holds true for synthetic biology, which has also been called engineering biology. However, the ability to repeat measurements in different labs has been difficult. This year is fourth InterLab study that organized by the iGEM Organization Measurement Committee. It aims to establish a GFP measurement protocol based on engineering principles that anyone with a plate reader can use in their lab and to improve measurement tools and methods in laboratory work.

The Interlab study required us to follow a standard protocol including transformation, incubation, plate reader calibration, florescence standard curve obtainment, cell culture florescence measurement, etc ( Detailed protocol information can be found at https://2017.igem.org/Competition/InterLab_Study ). During the whole Interlab study process, everyone, instructed by the team PI, studied the protocol carefully and worked on providing accurate and reliable experiment data to The Measurement Committee.

1.Transformation of the test devices and +/- control

Unfortunately, we had an unexplained problem while attempting to transform cells with the extracted DNA from the Distribution Kit Plates. Luckily, we heard from iGEM team Worldshaper-XSHS that they have successfully obtained the transformed colony but was unable to continue with the protocol due to lack of a plate reader in their lab. We invited representatives from Worldshaper-XSHS to join our Interlab project, providing transformed colony and they accepted our request. (To learn more about our cooperation, check out our Collaboration page.)

2.OD600 reference point measurement

We strictly followed the standard protocols provided by the Measurement Committee and turned off pathlength correction accordingly.

3.Fluorescein standard curve obtainment

We measured the fluorescence of 4 replicates of dilution series of fluorescein in PBS buffer. The results are as shown below.

4.Cell measurement

We had correctly diluted our overnight transformed cell culture to a target OD600 of 0.02. Then we incubated the diluted culture and took samples at 0,2,4,6 hours after dilution and held them on ice. Then we measured the florescence of these samples and the results are as shown below.

Raw plate readings

Adjusted results