It is a 166 amino acid protein produced by E. coli bacteria into which a gene has been inserted for soluble human stem cell factor.[2] It has a monomeric molecular weight of approximately 18,500 daltons and normally exists as a noncovalently associated dimer. The protein has an amino acid sequence that is identical to the natural sequence predicted from human DNA sequence analysis, except for the addition of an N-terminal methionine retained after expression in E. coli. Because Ancestim is produced in E. coli, it is nonglycosylated. Ancestim is supplied as a sterile, white, preservative-free, lyophilised powder for reconstitution and administration as a subcutaneous (SC) injection and is indicated for use in combination with filgrastim for mobilizing peripheral hematopoietic stem cells for later transplantation in certain cancer patients.[3]
^da Silva MG, Pimentel P, Carvalhais A, et al. (2004). "Ancestim (recombinant human stem cell factor, SCF) in association with filgrastim does not enhance chemotherapy and/or growth factor-induced peripheral blood progenitor cell (PBPC) mobilization in patients with a prior insufficient PBPC collection". Bone Marrow Transplant. 34 (8): 683–91. doi:10.1038/sj.bmt.1704602. PMID15322567. S2CID21830065.