The recent findings of Waldo et al. 1 demonstrate that the fusion of the green fluorescent protein (GFP) to insoluble proteins dramatically reduces its folding ability in prokaryotic cells.

Figure 1: Fluoresence and phase-contrast microscopic evaluation of murine hematopoietic colonies for GFP expression. Figure 3: GFP expression in peripheral blood leukocytes from a rhesus macaque ...