Figure 4From: Optimizing Escherichia coli as a protein expression platform to produce Mycobacterium tuberculosis immunogenic proteinsMALDI-TOF/TOF mass spectrum of the doubly-charged protein His- full2 . Two principal isoforms can be observed, corresponding to the natrium adduct (at 21557.68 m/z) and to the natrium/synapinic acid adduct (21668.3 m/z).Back to article page