Figure 4.

Microinjected BBT‐ and tail‐labeled mRNAs selectively express FLuc protein. U2OS cells (A) and HeLa cells (B) were microinjected with either 10 nM unmodified BBT‐ or tail‐labeled mRNA in 1× PBS and 0.025% 10 kDa Cascade Blue^® Dextran. Twelve hours after microinjection, cells were fixed in 4% formaldehyde solution, ethanol permeabilized, and stained with primary and secondary antibodies labeled with either Cy3 (A) or DyLight 650 (B) fluorophores. (A) Microinjected U2OS cells selectively express protein that colocalize exclusively with the Cascade Blue^® injection marker for both fluorescent tail‐labeled and unlabeled FLuc mRNA. As a control, microinjected RNase A‐treated fluorescent tail‐labeled FLuc mRNA did not express protein. (B) Microinjected fluorescent BBT‐labeled FLuc RNA into HeLa cells selectively expressed protein that colocalize with the cell injection marker, in contrast to noninjected cells.