Molecules of Equivalent GFP (MEG)
Fig.1. Spherotech yellow fluorescent particles (FP-0852-2) were calibrated to GFP copies per cell as measured by quantitative western blot. The data series "Cells" includes samples from four independent chemostat cultures. Each contained MC4100 with a plasmid-based GFP generator: pSB4A3-I7109, pSB4A3-I7107, pSB3K3-I7109 or pSB3K3-I7107, as noted.
[Fluorescence intensity] = 0.0025*[GFP copies/cell]-14.416
R^2 = 0.9684
From the standard curve above, FP-0852-2 beads represent ~370,000 MEG (+/-40%)