Matrix effect on the analysis of oligonucleotides by using a mass spectrometer with a sonic spray ionization source

Area of Science:

• Analytical Chemistry
• Biochemistry
• Molecular Biology

Background:

• Matrix components and impurities can interfere with DNA analysis.
• Understanding these matrix effects is crucial for accurate oligonucleotide analysis.

Purpose of the Study:

• To investigate the impact of various matrices on oligonucleotide analysis using ion-trap mass spectrometry.
• To evaluate the role of Tris buffer in mitigating negative matrix effects.

Main Methods:

• Analysis of oligonucleotides using an ion-trap mass spectrometer with a sonic spray ionization source.
• Systematic variation of inorganic salts (NaCl, MgCl2), dNTPs, Taq polymerase, and Tris concentrations.

Main Results:

• Inorganic salts (NaCl, MgCl2) at 10 microM depressed signal intensity by ~50%.
• dNTPs and Taq polymerase caused more severe signal depression.
• Tris (hydroxymethyl)aminomethane at ~500 microM enhanced signal intensity (3-5 fold for 6-mer and 20-mer oligonucleotides).
• Tris reduced the matrix effects of salts, dNTPs, and Taq.

Conclusions:

• Tris buffer plays a significant role in enhancing oligonucleotide signal intensity.
• Tris effectively mitigates inhibitory matrix effects in mass spectrometric analysis.
• Optimizing Tris concentration is key for improving oligonucleotide analysis accuracy.