Gene Imaging

We applied our PNA-RCA-FISH approach for  in situ detection of short, single-copy sequences within genomic DNA in human cells. We employed this technique for fluorescent imaging of unique target sites on human mitochondrial and autosomal DNA. Our approach has several advantages compared to standard FISH: it enables one to target and label an individual sequence element equivalent to the size of a PCR primer, the small size of the probes reduces any effects that probe incorporation has on the genome domain spatial arrangement, and denaturation of genomic DNA is omitted. The topological link between the target DNA and the circular probe ensures that the precisely positioned label has to occupy a fixed site along the double helix. It may serve as a method for highly localized detection of various marker sites within genomes.