Granulocyte macrophage colony-stimulating factor (GM-CSF) controls the production, differentiation, and function of granulocytes and macrophages. The active form of the protein is a homodimer. GM-CSF stimulates the growth and differentiation of hematopoietic precursor cells from various lineages, including granulocytes, macrophages, eosinophils, and erythrocytes.

This protein is produced in yeast as a single glycosylated peptide chain of 127 amino acids with a molecular weight of 26-32 kDa. Recombinant GM-CSF differs from native human GM-CSF by an arginine to leucine substitution at amino acid 23. The carbohydrate moiety of the recombinant form may be different than that of the native protein. rGM-CSF is purified by proprietary chromatographic techniques. The first five amino acids have been sequenced and found to be APARS.

The protein was lyophilized from a 1 mg/ml solution containing 10 mM phosphate buffer pH 7.0 containing mannitol and sucrose as stabilizers. The purity is greater than 97% as determined by reverse-phase HPLC and SDS-PAGE. The ED50 is determined by stimulation of human TF-1 cells and is less than 0.183 ng/ml, corresponding to a specific activity of 5,500,000 IU/mg.

Advanced Targeting Systems(ATS)位于美国加州圣地亚哥， 成立于1994年。 公司发起人Douglas Lappi和Ronald Wiley博士在实验室开发出先进的分子神经外科学研究技术。ATS主要生产用于科研和药物研发的靶向试剂，公司在疼痛和药物转运的研究及临床治疗的两个产品已获专利保护。目前，产品包括靶向毒素 (可提供基底前脑胆碱能神经元、去甲肾上腺素能和肾上腺素能神经元、巨噬细胞和小胶质细胞的特异性损伤试剂等)、二抗生物素、神经元抗体、神经递质抗体、蛋白质和荧光结合物、免疫毒素对照等。