Fig. 5. Archvillin mRNA localizes to the tips of myotubes, in contrast to the more central distribution observed for mRNA encoding the ß-cardiac myosin heavy chain. Double labeling of a human 50MB-1 myotube with probes for (A) archvillin and (B) myosin heavy chain mRNAs. (C) The composite image shows archvillin (red), myosin heavy chain (green) and nuclear DNA (blue). Archvillin mRNA was hybridized using a cDNA probe labeled with digoxigenin-11-dUTP and detected with rhodamine-conjugated anti-digoxigenin; mRNA encoding the ß-cardiac myosin heavy chain was hybridized with a nick-translated probe containing biotin-16-dUTP and detected with FITC-conjugated avidin. DNA was labeled with 4',6-diamidino-2-phenylindole (DAPI). The most proximal of the centrally localized nuclei is at the left of the image. Bar, 5 µm.