Shav-Tal, et al (2004b): Box 2

Supplementary Material From Singer Lab Publications:

Imaging gene expression in single living cells

Nat Rev Mol Cell Biol 5(10):855-862 (2004 October)

Link to Journal | Download Reprint (PDF) | Figures | Movies | About the Authors

	Index Figure 1 Figure 2 Box 1 Box 2
	click image for larger view (view larger image at 100% magnification for best clarity)

Box 2. Labelling techniques for the detection of nucleic acids in living cells

DNA labelling

A tandemly repeated array (256 copies) of the lac operator (lacO) sequence is inserted into a chromosome. A fluorescent protein (XFP) is then artificially tethered to this specific DNA sequence by fusion to the DNA-binding lac-repressor protein (lacI), which binds these repeats and thereby allows for the detection of the integration locus in living cells (see figure, panel a).

RNA labelling

RNA molecules are detected using a fusion protein that comprises green fluorescent protein (GFP) and the MS2 bacteriophage coat protein, which has an extremely high affinity for a short RNA-recognition motif that is derived from the phage genome. Single mRNA molecules that contain as few as 24 MS2 RNA repeats can be detected (see figure, panel b).