CD19 is a 120 kDa transmembrane glycoprotein with a reduced MW of 95 kDa (Pezzutto, 1987; Sato, 1997). CD19 is a member of the immunoglobulin superfamily with two extracellular C2-type domains (Pezzutto, 1987), and it is a critical signal transduction molecule that regulates B lymphocyte development, activation, and differentiation (Sato, 1997). CD19 expression is restricted to B cells, being absent from T cells, monocytes, and granulocytes (Pezzutto, 1987). The CD19 antigen appears early during B cell maturation, probably at late pro-B cell stage around the time of Ig heavy chain rearrangement. It then persists during all stages of B cell maturation and is lost upon terminal differentiation to plasma cells (Pezzutto, 1987).，官网链接：https://www.sigmaaldrich.cn/product/mm/fcmab184f 默克 科研、开发、生产。 作为生命科学行业的全球领先供应商，我们致力于为科研、生物技术开发和生产，以及制药药物疗法开发和生产提供各类解决方案和服务。

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