Chromatography is a technique used to separate target biomolecules, such as proteins or nucleic acids, from complex mixtures. Liquid chromatography is frequently used in life science research and manufacturing. Common methods include:
- Size exclusion chromatography or gel filtration chromatography
- Hydrophobic interaction chromatography (HIC)
- Ion exchange chromatography
- Affinity chromatography
- Multimodal or mixed-mode chromatography
Chromatography instruments vary widely in size and purpose: systems may be designed for small research labs, for mid-phase clinical manufacturing, or for large-scale manufacturing. Systems can be very complex but often include some configuration of inlet valves, pumps, and tubing to move the sample through the system, sensors that measure pH, conductivity, temperature, or optical density of the sample before or after it passes through the stationary phase, a column or other unit that holds the stationary phase, and tubing and outlets for waste and eluent. A computer interface and software are used to program or start a chromatography run, set reaction parameters, and view system status and run data. ÄKTA™ chromatography instruments from Cytiva run on UNICORN™ software.
Common valves used in chromatography systems include:
- Inlet valves for sample loading
- Outlet valves for waste and fraction collectors
- Injection valves for introducing precise sample volume to the column
- Column valves that may include reverse flow or bypass functionality
- Filter and pH calibration valves
- Loop valves
- Manual diaphragm valves
- Mixer valves
Applications of chromatography
Chromatography systems are often used for protein purification, which is the isolation of a target protein from a complex mixture such as a cell lysate. Protein purification can be analytical or preparative. Analytical purification produces low quantities of protein for research or analytical purposes, such as quantification and identification. However, preparative purifications aim to create large amounts of purified proteins, such as monoclonal antibodies, for subsequent use.
In addition to protein purification, chromatography can be used to purify plasmids, mRNA, and adeno-associated virus (AAV).
Chromatography valves FAQs
Here are answers to some frequently asked questions about chromatography valves.
What is a chromatography valve?
Valves for chromatography are components of a liquid chromatography system that act as switches to control the flow path of the system.
How are chromatography valves used?
Valves for chromatography help in sample injection, eluent selection, column selection, fractionation, and switching tasks. Since they support manual or automated driving through valve drives, these valves offer increased versatility.
What are they made of?
Made from various materials, including components in polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), titanium, or stainless steel, chromatography valves are designed to withstand use in intensive applications.