Sigma-Aldrich Bioshell A120 Oligo C18 2.7Um 50X3.0Mm

BIOshell A120 OLIGO C18 is a high-performance liquid chromatography column based on the Fused-Core^® particle design, enabling high throughput applications. This particle design exhibits very high column efficiency due to the shallow diffusion paths in the 0.5 µM deep porous shell and the small overall particle size of 2.7 µM.

BIOshell A120 OLIGO C18 has a surface modification that leads to alkaline resistance that provides a stable, reversed-phase packing that can be used for separations of oligonucleotides up to 60 bases at high pH mobile phaseconditions.

BIOshell A120 OLIGO C18 uses surface passivated column hardware to eliminate non-specific adsorption.

The BIOshell A120 OLIGO C18 bonded phase is a dimethyloctadecylsilane that has been specifically designed for applications requiring mobile phases that are mixtures of methanol and water or acetonitrile and water with mobile phase buffers or additives such as HFIP/TEA and TEAA. Using elevated temperatures (e.g., 40 – 60 ºC) will reduce the viscosityof the mobile phase and allow the use of faster flow rates and lower column pressure for high sample throughput. Gradient elution may start at 5% organic and then increase to a higher organic concentration depending on the length and sequence of the oligomers being analyzed. BIOshellA120 OLIGO C18 columns are highly suited for ion pair reversed-phase separationof oligonucleotides up to 60 bases. Additional information on solvent selection and separation techniques can be found in Chapter 13, Practical HPLC MethodDevelopment, Second Edition, L.R. Snyder, J.L. Glajch, and J.J. Kirkland, (JohnWiley & Sons, 1997). The use of MS detectors may require additional considerations for ionization efficiencies and ionization suppression for choices of mobile phase additives. For more information, see Mobile Phase Aging and Its Impact on Electrospray Ionization of Oligonucleotides in J. Am. Soc. MassSpectrom. 2023, 34, 12, 2691–2699. (https://doi.org/10.1021/jasms.3c00264).

To maximize column life, ensure that samples and mobile phases are particle-free. The use of guard columns or an in-line filter with 0.5 µM porosity between the sample injector and the column is highly recommended. Should the operating pressure of the column suddenly increase beyond normal levels, reversing the flow direction of the column may be attempted to remove debris on the inlet frit. Long-term storage of silica-based, reversed-phase columns is best in 100% acetonitrile. Columns maybe safely stored for short periods (up to 3 or 4 days) in most common mobile phases. However, when using buffers, it is best to protect both the column and the HPLC equipment and remove the salts by flushing the column with the same mobile phase without the buffer (e.g., when using 60/40 MeCN/buffer, flush the column with 60/40 MeCN/H2O) to eliminate any danger from corrosion from the salts while providing rapid re-equilibration of the column with the original mobile phase. Before storing the column, the end-fittings should be tightly sealed with the end-plugs that came with the column to prevent the packing from drying.

Fused-Core is a registered trademark of Advanced Materials Technology, Inc.