Producers 
Sigma Aldrich
Germany
Aldrich
Aldrich is a supplier in the research and fine chemicals market. Aldrich provides organic and inorganic chemicals, building blocks, reagents, advanced materials and stable isotopes for chemical synthesis, medicinal chemistry and materials science. Aldrich's chemicals catalog, the "Aldrich Catalog and Handbook" is often used as a handbook due to the inclusion of structures, physical data, and literature references. Many students use it as a reference book, especially undergraduates, as it is offered free by request.
Sigma
Sigma is the Sigma-Aldrich's main biochemical supplier, with offerings including antibiotics, buffers, carbohydrates, enzymes, forensic tools, hematology and histology, nucleotides, proteins, peptides, amino acids and their derivatives.
Sigma RBI
Sigma RBI produces specialized products for use in the field of cell signaling and neuroscience. Their offerings range from standard biochemical reagents to the latest cutting–edge research tools, including new ligands for receptors and ion channels, novel enzyme inhibitors, phosphospecific antibodies, key signal transduction enzymes, and assay kits for cell signaling.
ISOTEC
ISOTEC provides isotopically labeled products for protein structure determination, peptide synthesis, proteomics, metabolic research, magnetic resonance imaging, nuclear magnetic resonance, breath test substrates, agriculture, as well as gas and gas mixes.
Fluka
Fluka manufactures chemicals and reagents for analytical, organic and biochemical research, and intermediates for the chemical and pharmaceutical industries.
Supelco
Supelco is the chromotography products branch of Sigma-Aldrich. It provides chromatography columns and related tools for environmental, government, food and beverage, pharmaceutical, biotechnology, medical and chemical laboratories; sample preparation products and chemical reference standards.
Sigma-Aldrich Fine Chemicals
Sigma-Aldrich Fine Chemicals (SAFC) is the fine chemical supply branch of Sigma-Aldrich specializing in raw materials for cell culture products; customized services for raw materials, manufacturing of active pharmaceutical ingredients.
Sigma Life Science (formally Sigma-Genosys)
Sigma Life Science provides products such as custom DNA/RNA oligos; custom DNA and LNA probes; siRNA; isotopically-labelled peptides and peptide libraries.
