DNAoligo

DNAoligo, commonly written as DNA oligo or DNA oligonucleotide, refers to a short single-stranded DNA sequence used as a building block or probe in molecular biology. These synthetic sequences are typically 15 to 100 nucleotides long and are custom manufactured for a specified sequence.

Synthesis is performed by automated DNA synthesizers using solid-phase phosphoramidite chemistry. Purification removes truncated products, commonly by desalting, high-performance liquid chromatography (HPLC), or polyacrylamide gel electrophoresis (PAGE). Oligos may carry modifications such as fluorescent labels, biotin, quenchers, or backbone changes (for example, phosphorothioate) to adjust stability, binding, or detection.

Applications include primers for PCR and sequencing, probes for qPCR or hybridization assays, DNA barcodes for multiplexing, templates for mutagenesis or gene assembly, and antisense sequences in research contexts. In genome editing workflows, DNA oligos can act as donor templates or guide-associated sequences in combination with other components.

Design considerations include length, GC content, and melting temperature, as well as avoiding secondary structures and primer-dimer formation. Modifications may be chosen for stability or detection, and synthesis quality is specified as purity, desalt versus HPLC- or PAGE-purified products.

Quality control typically measures concentration by UV absorbance at 260 nm and assesses purity by A260/A280 ratios, with analytical methods such as capillary electrophoresis or mass spectrometry used for verification.

DNA oligos have become a foundational tool in modern biology since automated DNA synthesis emerged in the late 20th century, enabling rapid, customizable production for research, diagnostics, and biotechnology.