FIGURE 3.

Kinetics of hybridization of molecular beacons to chicken embryonic fibroblast β-actin mRNA. (A) Comparison of the kinetics of in vitro hybridization of free molecular beacons (continuous line) with molecular beacons linked to streptavidin (broken line). Fluorescence intensity is plotted as a function of time after the addition of a synthetic β-actin mRNA transcript. (B) Changes in total cellular fluorescence after injection of a mixture of streptavidin and biotinylated molecular beacons. Three of the molecular beacons in the mixture were labeled with TMR and were specific for β-actin mRNA (solid circles), and one was labeled with Texas red and had no target mRNA in the cells (open circles).