Primary Proteins:
  1. mVenus
  2. SCFP1
  3. SCFP2
  4. SCFP3A
  5. SCFP3B
  6. SYFP2
    Secondary Proteins:
  1. ECFP,
  2. EYFP,
  3. EYFP-Q69K,
  4. Venus

Bleach Measurements

Protein (state) t1/2 (s) Power Light Mode In Cell Fusion ˚C
ECFP 85.0
Venus 15.0
A caution on interpretation of photostability measurements
Add photostability measurements


We created monomeric optimized variants of ECFP and EYFP, which fold faster and more efficiently at 37°C and have superior solubility and brightness. Bacteria expressing SCFP3A were 9-fold brighter than those expressing ECFP and 1.2-fold brighter than bacteria expressing Cerulean. In HeLa cells, the improvements were less pronounced; nonetheless, cells expressing SCFP3A and SYFP2 were both 1.5-fold brighter than cells expressing ECFP and EYFP(Q69K), respectively.

Changing leucine68 back to valine decreased the relative bleaching time of SYFP2 by 30%. Thus, mutation V68L contributes to the photostability of YFP.