The Cover

Labeling of human telomeres on metaphase chromosomes of a normal human fibroblast using digital fluorescence microscopy. Dual color telomeric chromosome orientation-fluorescence in situ hybridization (CO-FISH) was used to probe human telomeres using oligonucleotide N3'→ P5'--phosphoramidate probes specific for leading strand of telomere DNA sequences (green), lagging strand of telomere DNA sequences (pink), and the general DNA dye DAPI (blue). For details, see J. W. Shay, in this issue. (The strand-specific telomere probes were provided by Dr. Sergei Gryaznov, Geron Corporation (Menlo Park, CA) and the digital image was taken by Dr. Ying Zou.)