Chromatography membranes are designed for separation tasks in laboratory and industrial applications. They are built-in membrane systems such as plate and frame, spiral-wound module, hollow fibre module, and tube-in-shell module. Chromatography membranes have high throughput capabilities and high binding capacities. Some are inherently hydrophilic and characterized by low fouling. Comparable in cost to reusable resins and resin-based chromatographic media, specialty chromatography membranes are often used in highly-selective chromatographic separations. Proprietary products may consist of a polymeric hydrogel within a porous, flexible matrix that provides mechanical support. Chromatography membranes are used in both laboratory-scale and process-scale applications. Typically, bench-scale users employ chromatography membranes for purifying small amounts of biomolecules. In such applications, separation efficiency and productivity are important considerations. Chromatography membranes are also used in a variety of process-scale applications. Single-use and multi-cycle disposable products are designed to prevent batch-to-batch contamination. Chromatography products that provide scalability, a smaller footprint, and lower buffer usage are also available. When selecting chromatography membranes, an understanding of application requirements is important. Many chromatography membranes use ion exchange or affinity chemistries. Ion exchange chromatography involves either anion exchangers or cation exchangers, depending on the membrane’s specialized chemistry. Anion exchangers are used with negatively-charged biomolecules such as DNA and viruses. Cation exchangers are used with positively-charged biomolecules such as salts and metal ions. Both types of ion exchange chromatography membranes have high binding capacities, and may be used with proteins. Chromatography products for immobilized metal affinity chromatography (IMAC) chemistries are also available. Typically, these chromatography membranes are used in the purification of proteins or antibodies. Selecting chromatography membranes requires an understanding of not only ion exchange chromatography and affinity chromatography, but also of hydrophobic, interaction, reversed-phase and multistage chromatography. Typically, reversed-phase chromatography is used in liquid chromatography where the mobile phase is significantly more polar than the stationary phase. Other types of membrane chromatography are used in various medical and pharmaceutical applications, but especially in the separation of proteins. As a rule, synthetic chromatography membranes are better support matrices than conventional bead supports. Because they are not compressible, synthetic membranes eliminate diffusion limitations and offer higher throughput and faster processing times.