||Patterson G, Day RN, Piston D. Fluorescent protein spectra, J Cell Sci. 2001 Mar114(Pt 5):837-8. p.838 table 1 link - link PubMed ID11181166
||The cDNA of each GFP was subcloned to produce an N-terminal His6 fusion protein. His6-tagged GFPs were expressed in E. coli grown at 37°C, and purified on a Ni NTA agarose column. Fluorescence excitation and emission spectra were measured and quantum yields were determined by using either fluorescein (QY = 0.85) or 1- aminoanthracene (QY = 0.61) as a reference standard.
||Protein originally from Aequorea victoria, several rounds of optimziations via mutations were performed