Focused upon hybridization: rapid and high sensitivity detection of DNA using isotachophoresis and peptide nucleic acid probes.
We present a novel assay for rapid and high sensitivity detection of nucleic acids without amplification. Utilizing the neutral backbone of peptide nucleic acids (PNA), our method is based on the design of low electrophoretic mobility PNA probes, which do not focus under isotachophoresis (ITP) unless bound to their target sequence. Thus, background noise associated with free probes is entirely eliminated, significantly improving the signal-to-noise ratio while maintaining a simple single-step assay requiring no amplification steps. We provide a detailed analytical model and experimentally demonstrate the ability to detect targets as short as 17 nucleotides (nt) and a limit of detection of 100 fM with a dynamic range of 5 decades. We also demonstrate that the assay can be successfully implemented for detection of DNA in human serum without loss of signal. The assay requires 15 min to complete, and it could potentially be used in applications where rapid and highly sensitive amplification-free detection of nucleic acids is desired.
Faculty of Mechanical Engineering, Technion-Israel Institute of Technology , Haifa 3200003, Israel.
Nadya
N
Ostromohov
Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel.
Ortal
O
Schwartz
Faculty of Mechanical Engineering, Technion-Israel Institute of Technology , Haifa 3200003, Israel.|Russell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology , Haifa 3200003, Israel.
Moran
M
Bercovici
D004247:DNA / Q000032:analysis* / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D057625:Isotachophoresis / Q000379:methods*; D057230:Limit of Detection; D009693:Nucleic Acid Hybridization / Q000379:methods*; D015345:Oligonucleotide Probes / Q000737:chemistry*; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D059629:Signal-To-Noise Ratio; D013997:Time Factors
D015345:Oligonucleotide Probes; D020135:Peptide Nucleic Acids; D004247:DNA