Figure 2

Fluorescence of DsRed2 protein is not affected in RNAlater. (A & B) FACS results. All data in FACS figures are restricted to single cells defined by forward and side light scatter; clumped and ruptured cells (debris) are not displayed in the figure. DsRed positive and negative COS-7 cells were mixed before flow cytometry sorting. (A) Cells in BSA: a population of DsRed2 positive cells is clearly distinguished from DsRed2 negative cells. The cells with intermediate fluorescence intensity between the positive and negative populations represent newly dividing cells, which are in the initial stages of DsRed expression. (B) Cells in RNAlater: fewer cells are shown here than in (A) because RNAlater has induced cell clumping, so fewer singlets are available to the sorter. RNAlater did not quench fluorescent signals from analyzed DsRed positive cells. (C & D) Dissociated cells were observed under the fluorescence microscope (C) DsRed2 positive cells in BSA. (D) DsRed2 positive cells after addition of RNAlater. The intensity of the DsRed2 was stable in the presence of RNAlater. (C & D) Exposure time: 30ms; scale bar: 50 microns.