Oligonucleotide Analytical Services
Oligonucleotide therapeutics require specialized analytical strategies to characterize molecular identity, purity, sequence integrity, chemical modifications, impurities, and product quality. Analytical methods must be capable of distinguishing the intended full-length oligonucleotide from closely related impurities and degradation products while providing reliable data throughout development and manufacturing.
Protheragen provides comprehensive oligonucleotide analytical services covering identity and structural characterization, purity and impurity profiling, quantitative analysis, analytical method development and validation, physicochemical characterization, and stability-related testing. These services support oligonucleotide programs from early development and process optimization through drug substance and drug product manufacturing.
Overview of Oligonucleotide Analytical Services
Oligonucleotide analytical services encompass a range of analytical techniques used to characterize the chemical, structural, physical, and quality attributes of oligonucleotide drug substances and drug products. Unlike many conventional small-molecule APIs, oligonucleotides are sequence-defined molecules that can generate closely related impurities during synthesis, deprotection, purification, formulation, and storage.
Comprehensive characterization therefore requires analytical approaches capable of evaluating the intended oligonucleotide as well as truncated sequences, failure sequences, modified species, degradation products, residual process-related impurities, and other product-related variants.
Key analytical considerations include identity, sequence integrity, purity, assay, molecular mass, modification status, impurity profile, aggregation, physical properties, and stability. Appropriate analytical methods and orthogonal techniques can be combined to provide a more complete understanding of oligonucleotide quality and support development of robust control strategies.
Fig.1 Typical composition of LNPs. (Ryan JP, et al., 2025)
Our Services
Comprehensive analytical characterization is essential for evaluating the identity, purity, structural integrity, and overall quality of oligonucleotide drug substances and drug products. Because oligonucleotides can generate closely related sequence variants, modified species, and degradation products, a combination of complementary analytical approaches may be required. The following services cover key analytical activities supporting oligonucleotide characterization, method development, impurity assessment, stability evaluation, and quality control.
Identity & Structural Characterization
Oligonucleotide identity and structural attributes are evaluated using appropriate analytical techniques to confirm the intended sequence, molecular mass, chemical modifications, and overall molecular structure. Structural characterization helps verify that the manufactured material corresponds to the intended oligonucleotide design.
Purity & Impurity Profiling
Purity analysis evaluates the full-length oligonucleotide and related impurities generated during synthesis, purification, processing, or storage. Analytical methods can be applied to characterize truncation sequences, failure sequences, modified species, and degradation products.
Sequence & Molecular Mass Analysis
Sequence and molecular mass characterization provides evidence for the identity and structural integrity of oligonucleotide drug substances. Appropriate mass spectrometric and chromatographic approaches can be used to assess molecular mass and sequence-related attributes.
Quantitative Assay & Content Determination
Quantitative analytical methods are used to determine oligonucleotide content or concentration and support material characterization, formulation development, in-process testing, and finished-product release.
Physicochemical Characterization
Physicochemical properties can influence oligonucleotide stability, formulation behavior, purification performance, and drug product quality. Analytical evaluation may include parameters such as molecular size, aggregation, charge-related characteristics, thermal behavior, pH, osmolality, and other product-specific attributes.
Process-Related Impurity Analysis
Residual impurities originating from oligonucleotide synthesis and downstream processing may include residual reagents, solvents, protecting-group-related species, catalysts, salts, and other process-related components. Appropriate analytical methods can be developed to detect and quantify relevant residual impurities.
Analytical Method Development & Validation
Analytical methods are developed or optimized according to the characteristics of individual oligonucleotide molecules and their intended testing purposes. Where required, methods can be validated to demonstrate appropriate specificity, accuracy, precision, linearity, range, robustness, and other relevant performance characteristics.
Stability-Indicating Analysis
Stability-indicating analytical methods are used to monitor changes in oligonucleotide quality during storage and under stress conditions. These methods help detect degradation products and changes in purity, identity, assay, or other critical quality attributes.
Analytical Techniques for Oligonucleotide Characterization
Depending on molecule type, chemical modification, development stage, and analytical objective, complementary chromatographic, spectrometric, and physicochemical techniques can be applied.
| Analytical Objective |
Representative Techniques |
| Identity |
LC, MS, LC-MS |
| Molecular Mass |
Mass Spectrometry |
| Purity |
HPLC, UPLC, LC |
| Sequence Characterization |
LC-MS / MS-based approaches |
| Related Substances |
Ion-Pair RP-HPLC, IEX, LC |
| Aggregation / Molecular Size |
SEC and related size-based methods |
| UV Quantification |
UV-Vis Spectroscopy |
| Thermal Properties |
DSC / thermal analysis |
| pH |
pH Measurement |
| Osmolality |
Osmolality Testing |
| Residual Solvents |
GC-based Analysis |
| Elemental / Metal Impurities |
ICP-MS / ICP-based Analysis |
| Degradation Products |
Stability-Indicating LC / LC-MS |
The specific analytical platform is selected according to the oligonucleotide chemistry, formulation, matrix, target attribute, and intended use of the method.
Oligonucleotide Impurity Analysis
Impurity characterization is an important component of oligonucleotide analytical development because impurities can originate from multiple stages of synthesis, purification, formulation, and storage.
Truncation & Failure Sequences
Incomplete coupling, capping, deprotection, or other synthesis-related events can generate shorter sequences and failure products. Chromatographic methods can be used to separate and monitor these closely related impurities.
Modified Oligonucleotide Impurities
Side reactions during synthesis or processing may produce modified oligonucleotide species. Appropriate analytical techniques can be applied to detect and characterize these variants.
Degradation Products
Hydrolysis, oxidation, deamination, depurination, or other chemical pathways may generate degradation products during storage or processing. Stability-indicating methods can be used to monitor these changes.
Process-Related Residuals
Residual solvents, reagents, salts, metals, protecting-group-related substances, and other process-related components may require evaluation depending on the manufacturing process and product requirements.
Stability & Degradation Analysis
Analytical testing plays an important role in understanding the stability of oligonucleotide drug substances and drug products. Stability-related analytical programs include:
Monitoring of product quality under proposed storage conditions to evaluate changes in identity, purity, assay, and degradation profile.
Evaluation under elevated stress conditions to identify potential degradation trends and support formulation and packaging development.
Controlled exposure to relevant stress conditions to investigate degradation pathways and establish stability-indicating analytical methods.
Assessment of potential changes in oligonucleotide quality following light exposure where relevant to the product.
Evaluation of product quality following preparation, handling, dilution, or administration under representative conditions.
Why Choose Protheragen
- Oligonucleotide-Specific Analytical Strategy
Analytical programs are designed around the sequence, chemical modifications, molecular characteristics, and development requirements of individual oligonucleotide products.
- Integrated Analytical Capabilities
Identity, purity, impurity, physicochemical, stability, and quality testing can be coordinated within an integrated analytical development program.
- Orthogonal Characterization
Complementary analytical techniques can be combined to provide more comprehensive characterization of oligonucleotide drug substances and drug products.
- Development-to-Release Support
Analytical services can support programs from early characterization and process development through method validation, clinical manufacturing, stability testing, and release testing.
- Flexible Analytical Development
Methods can be developed, optimized, qualified, validated, or transferred according to the analytical requirements and development stage of each project.
Oligonucleotide analytical activities can be coordinated with process development, formulation development, manufacturing, impurity research, and stability studies to support an integrated CMC strategy.
Protheragen provides specialized analytical support for oligonucleotide drug substance and drug product development, helping clients characterize molecular identity, purity, impurities, physicochemical properties, stability, and critical quality attributes. Contact us to discuss your oligonucleotide analytical requirements and develop an analytical strategy tailored to your molecule, formulation, manufacturing process, and development stage.
Reference
- Ryan JP, et al. "Increasing Oligonucleotide Sequencing Information and Throughput with Ion Mobility Spectrometry-Mass Spectrometry." J Am Soc Mass Spectrom. 2025; 36(7):1493-1502.
