Absolute Quantification of Oligonucleotides by ICP-MS/MS

Quantifying oligonucleotides accurately is a critical requirement throughout drug development and manufacturing, as concentration directly impacts both product efficacy and patient safety. While UV spectroscopy remains the most commonly used technique, it relies on either a well-characterised reference standard or prior knowledge of the oligonucleotide extinction coefficient.

This application note presents an alternative approach based on phosphorus determination by triple quadrupole ICP-MS/MS. By measuring phosphorus content and using the known molecular composition of the oligonucleotide, this method enables absolute quantification without requiring an oligonucleotide reference standard. The study evaluates the method’s precision, accuracy and suitability for purified therapeutic oligonucleotides.

Download the full technical application note to explore the methodology and performance data.

Method performance at a glance

• No oligonucleotide reference standard is required: only a certified phosphorus standard is used
• Applicable to purified oligonucleotide drug substances and drug products
• Precision showed relative standard deviations between 0.2% and 0.4%, while mean recoveries ranged from 99.8% to 102.4%

Supporting reliable oligonucleotides quantification strategies

Reliable concentration data are essential for product characterisation and analytical development. This ICP-MS/MS approach provides a quantitative solution that can be implemented independently of oligonucleotide-specific reference materials

• Enables absolute quantification of purified oligonucleotides
• Supports the characterisation of oligonucleotide materials during development.
• Can be used to determine extinction coefficients for subsequent UV spectroscopy analysis
• Suitable for routine analytical workflows requiring reliable concentration assessment

The method provides a robust foundation for quantitative oligonucleotide analysis throughout product development and testing