What are Solid Supports?
Solid supports, commonly referred to as resins, are insoluble, functionalized polymeric or inorganic particles that serve as the foundational substrate for solid-phase oligonucleotide synthesis (SPOS). These materials typically range from 50 to 200 micrometers in diameter and provide a stable, high-surface-area anchor onto which the oligonucleotide chain is assembled step-by-step using phosphoramidite chemistry. The choice of support directly impacts synthesis scale, efficiency, and final oligo quality.
Primary Types and Synthesis Functionalization:
- Controlled Pore Glass (CPG): The industry benchmark, CPG is a rigid, silica-based material featuring a highly controlled network of pores. This structure ensures efficient diffusion of synthesis reagents, enabling high coupling efficiencies—especially for long or complex sequences. CPG supports are typically functionalized with linkers (e.g., succinyl, aminoalkyl) that covalently bind the 3′-end of the initial nucleoside.
- Polystyrene (PS) Supports: A cost-effective organic polymer option, often used in large-scale synthesis. To mitigate inherent issues like swelling in organic solvents (which can reduce reagent accessibility and coupling consistency), our polystyrene supports are engineered with controlled cross-linking to improve dimensional stability.
Role in Oligonucleotide Synthesis:
During synthesis, the solid support is packed into a column where cyclic chemical steps—deprotection, coupling, capping, and oxidation—are performed. Its key functions include:
- Immobilizing the growing oligonucleotide chain.
- Enabling efficient reagent access and by-product removal.
- Allowing final cleavage and deprotection under specific conditions to release the desired oligo.
