Characterizing Chromoproteins

We encountered problems when measuring the the YFP-signal in our transformed C. rheinhardtii YFP strains, even though we were able to detect YFP when examining the cells with the fluorescence microscope. To get a better understanding of the protocols followed to measure absorbance and fluorescence spectra with a plate reader, we conducted some exemplary measurements with fluorescent and non-fluorescent chromoproteins expressed in E. coli. We tested three different chromoproteins from the iGEM Registry of Standard Biological Parts in terms of their absorption spectra (as well as the fluorescence spectrum in case of amajLime):

• amajLime from the coral Anemonia majato BBa_K1033914
• spisPink from the coral Stylophora pistillata BBa_K1033923
• gfasPurple from the coral Galaxea fascicularis BBa_K1033917