||Swaminathan R, Hoang CP, Verkman AS. Photobleaching recovery and anisotropy decay of green fluorescent protein GFP-S65T in solution and cells: cytoplasmic viscosity probed by green fluorescent protein translational and rotational diffusion. Biophys J. 1997 Apr72(4):1900-7.PubMed ID9083693
||according GFP lifetime and rotational correlation time. In solution lifetime=2.9 ns and rotational correlation time (tc) 20 ns. In cytoplasm lifetime=2.6 ns and rotational correlation time (tc) 36+-3 ns
||GFP mutant S65T was purified from recombinant bacteria for solution studies, and expressed in CHO cell cytoplasm.