Originally annotated as a monomer, M. tb ICD-2 exists as a homodimer. The elution profiles of recombinant M.tb ICD-2 on high performance column SuperoseTM 6 10/300 column. The lower panel of the chromatogram shows a peak corresponding to a tetramer (~320 KDa) under low salt condition, which was dissociated into a dimer (~180 KDa) at a high salt concentration of 1 M. The collected elution fractions run on 7% SDS-PAGE are shown under respective peaks. The upper panel represent chromatographic peaks corresponding to the protein markers; Thyroglobulin (669 KDa), Apoferritin (443 KDa), BSA (66 KDa) and Carbonic anhydrase (29 KDa). Inset: The calibration curve plotted as Ve/Vo versus log of molecular mass for calculating molecular weights of the oligomeric assembly.