A sequencing method for RNA oligonucleotides based on mass spectrometry

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• RNA sequencing is crucial for understanding biological processes.
• Existing mass spectrometry methods for RNA face challenges with read length, cost, and distinguishing uridine (U) and cytidine (C) due to similar masses.
• There is a need for faster, more cost-effective, and accurate RNA sequencing techniques.

Purpose of the Study:

• To develop a novel, non-gel-based, and non-labeling RNA sequencing strategy.
• To leverage matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) for RNA analysis.
• To overcome the limitations of distinguishing U and C in mass spectrometric RNA sequencing.

Main Methods:

• Sequencing of synthetic oligoribonucleotides up to 22 bases.
• Utilizing exonuclease-induced phosphodiester bond hydrolysis with differential kinetics.
• Detection and analysis of resulting fragments using MALDI-TOF-MS.
• Distinguishing uridine and cytidine by differences in peak intensities.
• Verification using specific endonucleases and 13C-labeled nucleotides.

Main Results:

• Successful sequencing of synthetic oligoribonucleotides.
• Demonstrated ability to differentiate between uridine and cytidine bases based on peak intensity.
• Achieved preparation and measurement times of less than 1 hour.
• Provided the first RNA sequencing data utilizing the advantages of MALDI-TOF-MS for this application.

Conclusions:

• The developed method offers a fast, accurate, and cost-effective approach for RNA sequencing.
• This nongel-based, nonlabeling strategy overcomes key limitations of existing mass spectrometry-based RNA sequencing.
• The technique holds promise for broader applications in RNA analysis and research.