[Skip to Content](https://www.sigmaaldrich.com#main-content) [![MilliporeSigma](https://www.sigmaaldrich.com/static/logos/purple/millipore_sigma.svg)](https://www.sigmaaldrich.com/US/en) Products Cart0 USEN Products ProductsApplicationsServicesResourcesSupport [Login / Register](https://www.sigmaaldrich.com/oidc-sign-in) [Order Lookup](https://www.sigmaaldrich.com/US/en/order-lookup) [Quick Order](https://www.sigmaaldrich.com/US/en/quick-order) Cart0 [Home](https://www.sigmaaldrich.com/US/en)[Applications](https://www.sigmaaldrich.com/US/en/applications)[Analytical Chemistry](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry)[Sample Preparation Techniques](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry/sample-preparation)Sample Purification # Sample Purification ![Graph illustrating the key stages of affinity chromatography separation involving bind, wash and elute steps.](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/applications/analytical-chemistry/typical-affinity-purification.png "Graph illustrating the key stages of affinity chromatography separation involving bind, wash and elute steps.") Various chemical and physical purification methods can be applied to separate or concentrate a target analyte prior to analysis. Among these are absorption, adsorption, chromatography, distillation, [](https://www.sigmaaldrich.com)[extraction](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry/sample-preparation/solid-phase-extraction), ion exchange, [](https://www.sigmaaldrich.com)[filtration](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry/sample-preparation/filtration), complex formation, crystallization, drying, and many more. Sample preparation prior to analysis helps bring a sample to a format that is compatible with the analytical technique, reduces sample complexity, removes interfering impurities, and concentrates the analyte prior to analysis. Appropriate sample preparation will prevent clogging, may reduce the need for stringent washing procedures, and can extend the life of the chromatographic medium.   * * * ## Related Products Slide 1 of 6 1 of 2 [![HiTrap® MabSelect™ PrismA Cytiva, 17549852, pack of 5 × 1 mL](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/images/129/798/0fb3ffed-63dc-4a0c-8810-9b7a08ebbbb5/640/0fb3ffed-63dc-4a0c-8810-9b7a08ebbbb5.jpg) \ GE17549852 \ HiTrap® MabSelect™ PrismA](https://www.sigmaaldrich.com/US/en/product/sigma/ge17549852) Quick View [![HisTrap™ Fast Flow Cytiva 17-5319-01, pack of 5 × 1 mL](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/images/276/619/dab7428c-2fbe-4fe6-921e-d414abf68f25/640/dab7428c-2fbe-4fe6-921e-d414abf68f25.jpg) \ GE17-5319-01 \ HisTrap™ Fast Flow](https://www.sigmaaldrich.com/US/en/product/sigma/ge17531901) Quick View [![MabSelect™ Xtra Cytiva 17-5269-02, pack of 200 mL](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/images/348/852/537377ee-0c1c-4a87-871c-0369367ed9cd/640/537377ee-0c1c-4a87-871c-0369367ed9cd.jpg) \ GE17-5269-02 \ MabSelect™ Xtra](https://www.sigmaaldrich.com/US/en/product/sigma/ge17526902) Quick View [![Amicon® Pro Purification System with Ultra-0.5 Device Amicon Pro Purification System - A 50 kDa Centrifugal Tool collapsing protein purifcation with concentraion & buffer exchange.](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/images/170/231/ada38963-75e3-4eac-a376-505829b1405d/640/ada38963-75e3-4eac-a376-505829b1405d.jpg) \ Millipore \ ACS5050 \ Amicon® Pro Purification System with Ultra-0.5 Device](https://www.sigmaaldrich.com/US/en/product/mm/acs5050) Quick View [![Amicon® Ultra Centrifugal Filter, 30 kDa MWCO sample volume 15 mL, regenerated cellulose membrane, MWCO 30 kDa](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/images/127/654/5c16f5d9-176f-4dd4-ac47-20f4fabf3406/640/5c16f5d9-176f-4dd4-ac47-20f4fabf3406.jpg) \ Millipore \ UFC9030 \ Amicon® Ultra Centrifugal Filter, 30 kDa MWCO](https://www.sigmaaldrich.com/US/en/product/mm/ufc9030) Quick View [![Ammonium sulfate BioXtra, ≥99.0%](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/structures/350/770/e906eba9-5b7c-4d73-8f25-c4c5e7e80f21/640/e906eba9-5b7c-4d73-8f25-c4c5e7e80f21.png) \ Sigma-Aldrich \ A2939 \ Ammonium sulfate](https://www.sigmaaldrich.com/US/en/product/sial/a2939) Quick View * * * ## Featured Categories [![A close-up view of an Amicon device used for filtration, featuring four transparent tubes arranged vertically within a black frame. The tubes contain different colored liquids, indicating varying concentrations or solutions. The device is positioned on a laboratory countertop, with visible tubing connected to the top and a base that appears to be designed for stability during operation.](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/categories/protein-biology/protein-sample-prep/amicon-ultra-filters.jpg "Amicon® Ultra filters")](https://www.sigmaaldrich.com/US/en/products/protein-biology/protein-sample-prep/amicon-centrifugals) [Amicon® Devices](https://www.sigmaaldrich.com/US/en/products/protein-biology/protein-sample-prep/amicon-centrifugals) Centrifugal and pressurized ultrafiltration devices for protein concentration, desalting, buffer exchange, separation, and diafiltration of biological and environmental samples in preparation for downstream applications. 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[Shop Products](https://www.sigmaaldrich.com/US/en/products/water-purification/milli-q-benchtop-water-purification-systems) [![A clear laboratory beaker filled with colorless liquid, containing a small cylindrical container with a red liquid inside. The container is topped with a blue lid, floating on the surface of the liquid in the beaker. The beaker has measurement markings on the side, indicating its volume.](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/categories/protein-sample-prep/d-tube-dialyzers.jpg "D-Tube™ Dialyzers")](https://www.sigmaaldrich.com/US/en/products/protein-biology/protein-sample-prep/laboratory-dialysis-and-diafiltration-devices) [Laboratory Dialysis & Diafiltration Devices](https://www.sigmaaldrich.com/US/en/products/protein-biology/protein-sample-prep/laboratory-dialysis-and-diafiltration-devices) Dialyzers, centrifugal ultrafiltration devices, and stirred cells for buffer exchange... 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[Shop Products](https://www.sigmaaldrich.com/US/en/products/analytical-chemistry/analytical-sample-preparation/spe-and-quechers) * * * Overview Related Articles & Protocols Support Some of the following most common purification techniques are used in the laboratory to prepare samples for downstream analysis. ## Dialysis Dialysis is a purification technique used to remove salt or other low molecular weight molecules from a sample. It is also used to exchange a sample’s buffer composition. Dialysis is a passive technique requiring large volumes of buffer. ## Buffer Exchange & Desalting Desalting is a simple method to remove salts and other low molecular weight contaminants from a sample. It is also used for buffer exchange before or after different chromatographic steps and for the rapid removal of reagents to terminate a reaction. ## Fractional Precipitation Fractional precipitation is used to remove gross impurities from small sample volumes. Precipitation techniques separate fractions by the principle of differential solubility. Because protein species differ in their degree of hydrophobicity, increased salt concentrations can enhance hydrophobic interactions between the proteins and cause precipitation. ## Extraction Sample preparation by extraction involves the isolation of target analytes from a complex sample, or much larger sample volume. The process removes interfering sample components that may block HPLC and GC columns. It also increases analyte concentration by a factor of 100 to 5,000, thereby significantly improving detection sensitivity. As part of selective and specific sample preparation, extraction helps ensure more reliable chromatographic analysis. Types of extraction are liquid-liquid extraction, [](https://www.sigmaaldrich.com)[solid phase extraction (SPE)](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry/sample-preparation/solid-phase-extraction), and [](https://www.sigmaaldrich.com)[solid phase microextraction (SPME)](https://www.sigmaaldrich.com/US/en/applications/analytical-chemistry/sample-preparation/solid-phase-microextraction). ## Affinity Chromatography Affinity chromatography separates proteins based on reversible interactions between a protein and a specific ligand that has been coupled to a chromatography matrix. The technique is highly selective and allows for high capacity protein purification.  Affinity chromatography can be used whenever a suitable ligand is available for the protein of interest. Purification by affinity chromatography involves capture and elution steps. In the capture phase, the target protein is specifically and reversibly bound to a complementary ligand that has been immobilized on a chromatography matrix. The objective is to isolate, concentrate, and stabilize the target product, conserving its potency and activity. After washing the matrix to remove unbound material, bound target protein is recovered by changing conditions to those favoring elution. Elution is performed specifically, using a competitive ligand, or nonspecifically, by changing the pH, ionic strength, or polarity. Elution allows the target protein to be collected in a purified and concentrated form. [![Document Search](https://www.sigmaaldrich.com/content/dam/cms-commons/sigmaaldrich/marketing/global/images/ecommerce/document-search.png "Document Search")](https://www.sigmaaldrich.com/documents-search) [Looking for More Specific Information?](https://www.sigmaaldrich.com/documents-search) Visit our document search for data sheets, certificates and technical documentation. [Find Documents](https://www.sigmaaldrich.com/documents-search) [Shop All Sample Purification Products](https://www.sigmaaldrich.com/search/sample-purfication?focus=products&page=1&perpage=30&sort=relevance&term=Sample%20Purfication&type=product) ## Related Articles - [Solvent Miscibility Table](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/solvent-miscibility-table) Substances are said to be miscible in one another if they dissolve to form a uniform solution. Bookmark or download our miscibility table for common lab solvents. - [Immobilized Metal Chelate Affinity Chromatography (IMAC)](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/metal-chelate-afnity-chromatography) How to separate proteins and peptides with affinity for metal ions by immobilized metal chelate affinity chromatography. - [Non-volatile and Volatile Buffer Systems](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/non-volatile-and-volatile-buffer-systems) This page shows volatile and non-volatile buffer suggestions for anion and cation exchange chromatography. - [Plasmid purification by ion exchange chromatography with Genopure kits](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/ion-exchange-chromatography) Ion exchange chromatography is employed by the Genopure Plasmid Midi Kit and the Genopure Plasmid Maxi Kit. - [Maintenance of Multimodal Chromatography Media and Storage Conditions](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/protein-biology/protein-purification/maintenance-of-media-and-storage-conditions) This page describes the maintenance of media and storage conditions for multimodal chromatography using Cytiva products. - [See All (29)](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) ## Related Protocols - [Converting From Linear Flow (cm/hour) to Volumetric Flow Rates (mL/min) and Vice Versa](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/analytical-chemistry/purification/converting-linear-flow-to-volumetric-flow-rates) This page shows how to convert between linear flow and volumetric flow rates in affinity chromatography. - [Column Packing & Separation with Sephadex® LH-20](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/analytical-chemistry/purification/performing-a-separation-with-sephadex-lh-20) Separation using Sephadex LH-20 column for Size Exclusion Chromatography media in polysaccharide network from Cytiva. - [Reverse Phased Chromatography (RPC) in Practice](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/analytical-chemistry/purification/reverse-phased-chromatography-in-practice) In this section the practical aspect of Reverse Phased Chromatography ( RPC) is discussed including media and column selection and eluent selection and preparation. - [Performing a Separation with Superose](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/analytical-chemistry/purification/performing-a-separation-with-superose) Superose from Cytiva are Size Exclusion Chromatography media consisting of a composite base matrix of dextran and agarose. This page shows how to perform a separation with a superose column. - [Removal of Detergents from Biological Product Matrices](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/analytical-chemistry/purification/detergent-removal-biologicals) The Amberlite™ XAD-4 resin used in Porozorb™ cartridges is a proven technology that is highly effective in removing various detergents from cell culture media for biopharmaceutical applications such as vaccine production. - [See All (44)](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) ### Find More Articles and Protocols Enter Keywords Search ## How Can We Help In case of any questions, please submit a [customer support request](https://www.sigmaaldrich.com/US/en/support/customer-support) or talk to our customer service team: Email [custserv@sial.com](mailto:custserv@sial.com) or call +1 (800) 244-1173 ## Additional Support - [Chromatogram Search](https://www.sigmaaldrich.com/chromatogram-search) Use the Chromatogram Search to identify unknown compounds in your sample. - [Calculators & Apps](https://www.sigmaaldrich.com/US/en/support/calculators-and-apps) Web Toolbox - science research tools and resources for analytical chemistry, life science, chemical synthesis and materials science. - [Customer Support Request](https://www.sigmaaldrich.com/US/en/support/customer-support) Customer support including help with orders, products, accounts, and website technical issues. - [FAQ](https://maestro.my.site.com/knowledgeportal/s/) Explore our Frequently Asked Questions for answers to commonly asked questions about our products and services. * * * * * * * * * __Featured Articles__ [Solvent Miscibility Table](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/solvent-miscibility-table) Substances are said to be miscible in one another if they dissolve to form a uniform solution. Bookmark or download our miscibility table for common lab solvents. [Immobilized Metal Chelate Affinity Chromatography (IMAC)](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/metal-chelate-afnity-chromatography) How to separate proteins and peptides with affinity for metal ions by immobilized metal chelate affinity chromatography. [Non-volatile and Volatile Buffer Systems](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/non-volatile-and-volatile-buffer-systems) This page shows volatile and non-volatile buffer suggestions for anion and cation exchange chromatography. [Plasmid purification by ion exchange chromatography with Genopure kits](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/analytical-chemistry/purification/ion-exchange-chromatography) Ion exchange chromatography is employed by the Genopure Plasmid Midi Kit and the Genopure Plasmid Maxi Kit. Top __Sign In To Continue__ To continue reading please sign in or create an account. 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