Large-scale SNP scoring from unamplified genomic DNA

Area of Science:

• Biotechnology
• Genomics
• Molecular Diagnostics

Background:

• The Human Genome Project (HGP) drives advancements in medical technology, increasing demand for genetic tests.
• Identifying single nucleotide polymorphisms (SNPs) linked to diseases necessitates efficient high-throughput screening (HTS) methods.
• Current SNP detection methods require improvement in cost-effectiveness, reliability, and throughput.

Purpose of the Study:

• To introduce and evaluate the Invader assay as a novel platform for SNP detection.
• To demonstrate the assay's capability for high-throughput, cost-effective genetic screening.
• To highlight the potential of the Invader assay in clinical diagnostics.

Main Methods:

• Utilizes a structure-specific 5' nuclease (flap endonuclease) for cleaving specific DNA structures.
• Employs two cascading reactions involving synthetic oligonucleotide probes and a FRET probe.
• Performs detection directly from unamplified genomic DNA without prior amplification.

Main Results:

• The Invader assay achieves high specificity and sensitivity in detecting single nucleotide changes.
• Significant signal amplification (over 10^6 cleaved probes per target molecule per hour) allows direct detection.
• Assay components for the secondary reaction are universal, adaptable to various targets.

Conclusions:

• The Invader assay is a simple, automatable, and cost-effective diagnostic platform for SNP scoring.
• Its high-throughput capability addresses the growing need for genetic testing in clinical laboratories.
• The technology facilitates direct detection of genetic variations from genomic DNA, streamlining diagnostics.