DNA quantification via ICP-MS using lanthanide-labeled probes and ligation-mediated amplification

Area of Science:

• Biochemistry
• Analytical Chemistry
• Molecular Biology

Background:

• Nucleic acid quantification assays require sensitive and specific detection methods.
• Lanthanide-tagged probes offer unique detection capabilities.
• Inductively coupled plasma mass spectrometry (ICP-MS) provides high sensitivity elemental analysis.

Purpose of the Study:

• To develop a novel labeling and analysis strategy for heterogeneous nucleic acid quantification.
• To combine lanthanide-tagged oligonucleotide probes with ICP-MS for enhanced detection.
• To improve sensitivity and sequence specificity using molecular biological techniques.

Main Methods:

• Hybridization assay using biotin-streptavidin affinity with lanthanide-labeled reporter and biotinylated capture probes.
• Detection via inductively coupled plasma mass spectrometry (ICP-MS).
• Integration of restriction endonuclease elution, ligase detection reaction (LDR) for signal amplification, and ligase chain reaction (LCR) for target amplification.

Main Results:

• A basic sandwich assay achieved a limit of detection (LOD) of 7.2 fmol DNA target.
• Enzymatic methods (restriction endonuclease, LDR, LCR) enhanced sequence specificity and sensitivity.
• Ligase chain reaction (LCR) resulted in a 6000-fold sensitivity increase.
• The optimized assay achieved an LOD of 2.6 amol for double-stranded DNA targets.

Conclusions:

• Lanthanide-tagged probes combined with ICP-MS offer a powerful strategy for nucleic acid quantification.
• Integration with enzymatic amplification techniques significantly boosts assay sensitivity and specificity.
• This approach enables highly sensitive detection of nucleic acid targets.