Stick With Me: The Cool Chemistry Of HILIC Oligonucleotide Analysis

Therapeutic oligonucleotides demand precise analysis, and while ion-pair reversed-phase LC remains the gold standard, it isn't always the best tool for highly polar or modified sequences. HILIC (Hydrophilic Interaction Liquid Chromatography) eliminates the need for ion-pairing reagents, offering a powerful alternative that leverages hydrophilic partitioning and electrostatic interactions for superior resolution. By maintaining a water-enriched layer on the stationary phase and utilizing high-organic mobile phases, scientists can achieve sharp separation compatible with mass spectrometry.

Success in this mode requires mastering specific parameters, from optimizing buffer pH to managing column equilibration times for consistent retention. As Part 4 of a 9-part series, this article explores how to dial in HILIC conditions to handle even the most stubborn analytes. Read the full article to refine your separation strategy.