PNA Probes and Detection System
Hybridization techniques are used to localize and identify specific nucleic acid sequences. Initially used as a research tool, the development of non-radioactive probe labeling and detection systems has made this technology available to a wide variety of routine applications. Traditionally either cloned probes or synthesized oligonucleotide probes have been used for hybridization. Dako has successfully introduced the peptide nucleic acid (PNA) probe, a nucleotide analogue capable of binding to DNA/RNA in a sequence-specific manner obeying the Watson-Crick base pairing rules.
In PNA, the sugar phosphate backbone of DNA/RNA has been replaced by a synthetic peptide backbone keeping the distances between bases exactly the same as in DNA/RNA. The increase in affinity is evident from the increase in the Tm of 1-1.5 °C per base pair. Further, the PNAs are very stable molecules. Experiments have shown virtually no degradation by DNases, RNases, proteinases or peptidases. The PNA probes are labeled with fluorescein and detected using Dako’s sensitive PNA ISH Detection Kit, Code K5201.