Concentration dependence of the apparent MW in size-exclusion chromatography experiments on EosFP and mutants. Fitted binding isotherms, calculated by assuming saturation levels at 40 and 66 kDa, are shown as solid lines. Data for the monomeric EGFP and tetrameric DsRed are included for comparison (⋆). ▪, wild type; ♦, d1EosFP; ▴, d2EosFP; •, mEosFP.