Recombinant AF Human Macrophage Colony-Stimulating Factor^ Recombinant Animal Free (AF) Human Macrophage Colony-Stimulating Factor (M-CSF AF) is a disulfide linked homodimer, containing two 159 AA chains, 8 kDa. Source: E.coli, lyophilized and stable at -20 degree C, Synonyms: mgI-IM, CSF-1, 10UG