Surface-based nucleic acid assays using morpholinos

This technology uses surface-bound morpholinos as probes in nucleic acid assays to capture and characterize nucleic acid sequences.

Unmet Need: Low-cost, robust nucleic acid assay

Surface-based nucleic acid assays are vital to technologies such as DNA microarrays. Current detection methods rely on the thermodynamics and hybridization kinetics of conventional nucleic acid probes (RNA or DNA) with nucleic acid baits. Because nucleic acid molecules are negatively charged, hybridization proceeds only in high ionic strength solutions. Therefore, these reactions rarely reach the equilibrium state, require wash steps for increasing specificity, and often utilize expensive probes.

The Technology: Surface-immobilized morpholinos for nucleic acid analysis

This assay detects nucleic acid molecules using morpholino probes anchored to a solid support. Morpholinos are non-ionic nucleic acid analogues that can hybridize with conventional nucleic acid molecules by base pairing in a sequence-specific manner. These probes are not charged, allowing reactions to proceed in low ionic strength solutions with great sequence binding specificity, reducing the risk of self-aggregation, avoiding undesired surface electrostatic interactions, and eliminating the need for a wash step. In addition, morpholinos cost less to produce in bulk than conventional nucleic acid strands.

This technology has demonstrated efficient DNA hybridization under a wide range of ionic strengths.

Applications:

• Pathogen detection
• Precision diagnostics
• Genotyping and transcriptome profiling
• Nucleic acid biosensor

Advantages:

• Suitable for microarrays
• Simple assay protocol
• Allows for label-free detection using electrostatic measurements
• Reasonably fast equilibrium
• Unhindered by electrostatic interactions
• Functions in low ionic strength solutions
• Robust
• Cost-effective

Lead Inventor:

Ken Shepard, Ph.D.

Patent Information:

Patent Status

Related Publications:

• Qiao W, Kalachikov S, Liu Y, Levicky R. “Charge-neutral Morpholino microarrays for nucleic acid analysis” Anal Biochem. 2013 Mar 15; 434(2): 207-214.

• Gong P, Wang K, Liu Y, Shepard K, Levicky R. “Molecular mechanisms in Morpholino-DNA surface hybridization” J Am Chem Soc. 2010 Jul 21; 132(28): 9663-9671.

Tech Ventures Reference:

• IR M07-104

• Licensing Contact: Greg Maskel