PNA (Peptide Nucleic Acid)

Overview

PNA (Peptide Nucleic Acid) was discovered by Nielsen, Egholm, Berg, and Buchardt in 1991.
PNA is a DNA analog in which polyamide backbone replaces the traditional phosphate ribose ring of DNA. Despite a radical change to the natural structure, PNA is capable of sequence-specific binding to DNA or RNA.

Due to its superior binding properties and stability, PNA has been widely applied in the field of biology.

Characteristics of PNA

• High binding affinity to complementary DNA or RNA
  
• More destabilizing effect by single-base mismatch.
  
• Resistant to nuclease and protease
  
• Hybridization with DNA independent of salt concentration
  
• Triplex formation with homopurine DNA

Comparison of PNA and DNA

Application of PNA

PNAs can be used in many of the applications where traditional synthetic DNA or RNA have been used, but with the added benefits of tighter binding, greater specificity and stability.

Materials for antigene and antisense therapy
The stronger binding properties and biological stability of PNA imply that a small quantity of PNA can be effective for therapeutic applications. Triplex invasion of a PNA shows good potential as antigene material. As a third generation molecule in antisense therapy, there has been experimental data that shows good effect in vitro and in vivo.

Molecular tools for molecular biology and functional genomics
PNA is used as tools of molecular biology and functional genomics research.

• Northern and Southern blot
  
• PCR clamping
  
• Enhanced PCR amplification
  
• Artificial restriction enzyme systems
  
• PNA-assisted rare cleavage
  
• DNA purification

Molecular probes for diagnostics and detection
Binding properties of PNA give more specific, more sensitive, and more accurate result for the detection of target sequences. Some of the commercialized PNA products available on the market are probes that detect genetic disease and or detect viral or bacterial infections.

• FISH probe (telomere detection kit)
  
• LightUp probe
  
• PNA probe for SNP detection
  
• PNA probe for microarray
  
• PNA probe for nucleic acid biosensor