The SIVmac239 gag (p55) is produced in E.coli. The recombinant p55-His tag is produced as a soluble protein. 

SIV gag is supplied as 1mg suspension in 10mM Tris, 150mM NaCl, 400mM Arginine.
 
Purity is verified by PAGE electrophoresis. For animal administration, the protein can be treated with Triton X-114 for removal of endotoxin and tested for the absence of endotoxin by LAL test.