Expression, purification, and characterization of protective MPT64 antigen protein and identification of its multimers isolated from nontoxic Mycobacterium tuberculosis H37Ra. 6 _; y! o& J) A8 t3 |- v) t! L0 I v8 R5 m1 { http://onlinelibrary.wiley.com/doi/10.1002/bab.26/abstract