Pierce Polyacrylamide Spin Desalting Columns, 7K MWCO, are pre-packed with porous polyacrylamide beads and enable buffer-exchange and desalting of proteins and other macromolecular samples based on a molecular-weight cutoff (MWCO) of 7000 Da. Unlike other size-exclusion media, polyacrylamide resin is not subject to enzymatic degradation and will not serve as a nutrient for microbial growth. The resin is very hydrophilic, thereby minimizing undesirable binding interactions between the resin and sample molecules. Contamination with low molecular weight sugars (which may occur with crosslinked dextran resin) is not a concern when using polyacrylamide resin. Oxidizing agents can be removed without destroying the support. This resin is susceptible to hydrolysis of amide groups under extreme pH conditions, so an operating pH of 2–10 is recommended at room temperature. The polyacrylamide resin can also be autoclaved at pH 5.5–6.5 for 30 minutes at 120°C.

The columns use a resin with beads that have a wet diameter of 45 to 90 μM and are ideal for separating peptides and small macromolecules (>7 kDa) from buffer salts and other compounds (less than 1K MWCO).

Features of polyacrylamide resin include:
• Stable in water, salt solutions, organic solvents, and alkaline or acidic conditions
• Excellent flow properties
• Heat stable

Applications
• Removing salts from protein solutions
• Removing phenol from nucleic acid preparations
• Separating excess crosslinker from conjugate preparations
• Removing excess derivatizing agents from modified proteins
• Removing unreacted dye from fluorescent antibodies
• Removing free radiolabel from labeled proteins
• Buffer exchange