The Custom Oligonucleotide Synthesis market is primarily divided by application and type. Application sub‑segments include Therapeutics (antisense, siRNA, aptamers), Diagnostics (fluorescent probes, qPCR primers, microarray tags), Research (CRISPR‑Cas9 guide RNAs, molecular‑biology primers) and Agriculture (pest‑control RNAs, GMO markers). Each sub‑segment contributes proportionally to market size: Therapeutics drives the highest revenue share due to clinical‑stage demand, Diagnostics follows with steady growth from personalized‑medicine testing, Research sustains a broad base of academic and biotech spend, while Agriculture remains niche but expanding in crop‑protection pipelines. Types of oligonucleotides further refine the taxonomy: standard DNA oligos, RNA oligos, and chemically modified oligos (e.g., LNA, PNA, phosphorothioate). Modified oligos command premium pricing because of enhanced stability and binding affinity, thereby amplifying their impact on total market valuation. This dual‑layer segmentation—application and type—forms the core of the Custom Oligonucleotide Synthesis and Gene Synthesis segmentation framework.