LSSmOrange:
LSSmOrange is an orange fluorescent protein that we want to use for FRET, we us it as a donor. In an actual paper Daria M. Shcherbakova[1] showed that LSSmOrange has an excitation maximum by 437 nm and an emission maximum by 572 nm. In the following diagram (figure 1) one can see our results with our own expressed LSSmOrange. The colored dots show the different maximums. The excitation maximum is at 415 nm, another at 453 nm and our measured emission maximum is at 564 nm. This aberration changes nothing on the FRET system. The excitation maximum is big enough to stimulate mKate, the other fluorescent protein. Of course, we checked also the emission and excitation of our Bl21DE3 cells (data not shown) and we can eliminate the theories that these cells disturb this florescence measurement.