LigAmp for sensitive detection of single-nucleotide differences.

Area of Science:

• Molecular Biology
• Genetics
• Biotechnology

Background:

• Accurate detection of specific DNA sequences, including mutations, is crucial for diagnosing genetic disorders, cancer, and infectious diseases.
• Existing methods may lack the sensitivity or accuracy required for early detection or precise quantification of low-prevalence mutations.

Purpose of the Study:

• To develop and validate the LigAmp assay for sensitive and accurate detection and quantification of DNA targets with single-base mutations.
• To assess the performance of LigAmp in detecting clinically relevant mutations, such as KRAS2 in cancer and K103N in HIV-1.

Main Methods:

• The LigAmp assay utilizes two adjacent oligonucleotides hybridized to a DNA template.
• Ligation of oligonucleotides occurs only if the target sequence, including a specific mutation, is present.
• Real-time PCR is employed for detection and quantification of the ligated products.

Main Results:

• LigAmp detected KRAS2 mutant DNA at 0.01% in cell line mixtures and in pancreatic duct juice from cancer patients.
• The assay identified the K103N HIV-1 drug resistance mutation at 0.01% in plasmid mixtures and ~0.1% in patient plasma DNA.
• Detection demonstrated linearity over a broad dynamic range, and multiplexing capabilities were preliminarily indicated.

Conclusions:

• The LigAmp assay provides sensitive and accurate detection and quantification of single-base mutations.
• This assay shows significant potential for diagnosing genetic disorders and managing patients with cancer and infectious diseases.
• LigAmp's ability to detect low-frequency mutations offers a valuable tool for clinical diagnostics and disease management.