sfGFP vs mRFP1

Improvement of an existing BioBrick

Our chosen target was Biobrick J04450 which is a mRFP Coding Device (link: http://partsregistry.org/Part:BBa_J04450). Its usage as a cloning tool has increased in time due to the easy detection of transformed colonies to the naked eye. Nonetheless, the advancement of automatic measurement systems and other modern technologies opens up a whole new range of applications in which markers are detected by highly sensitive machines and not by human observers. In these cases mRFP does not provide a significant advantage over other marker systems. In fact, it could diminish the efficiency of the experiment.

Therefore, we propose to exchange part mRFP for sfGFP. sfGFP would prove to be a better part for the following reasons:
sfGFP is of shorter length than mRFP1 (proposed implication: Lower metabolic cost. ) sfGFP has higher quantum yield/faster maturation rate or something of the sort!

To demonstrate the improvement of the BioBrick, we designed and run the following experiments:

Experiment : Culture growth

Three flasks were inoculated in equal concentrations with: psB4K5-J04450, psB4K5 – K743017 and wildtype TOP 10 cells respectively. Inoculum concentrations were checked by culture OD measurement at 600 nm to normalize the amount of bacteria that would be initially present.

Then, OD measurements at 600 nm, 584 nm and 492 nm were reported every 30 minutes for each of the flasks. 584 nm and 492 nm are the peak absortion wavelengths of mRFP1 and sfGFP respectively.

Insert:Explanation of why this should prove improvement

Results 1. Growth rate at 600 nm

Experimental data was adjusted

eq

curve

Results 2 Growth rate at 730 nm

Experimental data was adjusted

eq

curve References

Results 3.