美国西格玛Sigma-Aldrich是全球最大的化学试剂供应商，旗下包括Sigma、Aldrich 、Fluka、Rdh 等数个品牌，并且各个品牌涉及的领域都不相同，可以说Sigma-Aldrich公司的产品基本覆盖了化学试剂的各个领域。

Sigma-Aldrich in United States is the world's largest supplier of chemical reagents, including Sigma, Aldrich, Fluka, Rdh and other brands, and each brand involves different fields, it can be said that Sigma-Aldrich's products basically cover all fields of chemical reagents.