DNA and RNA oligonucleotides

Unmodified oligonucleotides are synthesized on an automated synthesizer by the phosphoramidite method. The synthesis technology allows oligonucleotides to be produced in the required quantities.

After synthesis, the oligonucleotide is cleaved from the polymer support, protecting groups are removed (deprotection), and the product is purified by reverse-phase HPLC or polyacrylamide gel electrophoresis. The oligonucleotides are supplied according to their passport data.

Ready for use

• Oligonucleotides are fully deprotected, purified by gel electrophoresis or HPLC, desalted, and quantitatively measured.
• They are normally supplied in deionized water (Milli-Q H₂O) or, on request, in lyophilized form.
• A synthetic oligonucleotide passport specifies the sequence, length, concentration, quantity, and molecular weight.

Quality control

• Systematic visual inspection: clear solution and no visible precipitate.
• Spectrophotometric analysis and concentration calculation.
• Purity control by gel electrophoresis using length markers.
• For modified oligonucleotides, the presence and functionality of the modification are checked: fluorescent labels by gel electrophoresis and UV visualization; biotin by electrophoretic and colorimetric analysis; amino groups by subsequent reaction with biotin; phosphate groups by alkaline-phosphatase hydrolysis followed by electrophoretic analysis.
• Analytical reverse-phase or ion-pair HPLC with a separation profile is available on request.

Storage recommendations

Oligonucleotides are stable in aqueous solution at 25°C for 1–2 weeks at concentrations above 150 ng/µL (20 µM). For longer storage or at lower concentrations, they should be kept frozen at −20°C. Frequent freeze-thaw cycles should be avoided when the concentration is below 100 ng/µL (15 µM). Fluorescently labeled oligonucleotides should be stored in the dark, and contact with non-sterile objects should be avoided, especially when working with enzymes and aggressive media.

When these storage conditions are observed, SYNTOL guarantees oligonucleotide quality for at least 12 months. Dilution and freezing below 15 µM can affect product quality during storage.