Fig. 7. Size exclusion chromatography of the native, DNase-treated and MNase-treated CRS2 complex. One microgram of stromal protein (A), stromal protein that had been treated with DNase I (B) or stromal protein that had been treated with MNase (C) was fractionated on a Superdex 200 gel filtration column. Column fractions were assayed for CRS2 by probing immunoblots with the CRS2 antibody. Twenty micrograms of stroma (str) were included for reference. The sizes of proteins in each fraction were calculated by comparison with molecular weight standards, and are indicated above each lane (in kDa). In (A) and (B), CRS2 was undetectable in fractions containing proteins <220 kDa. In (C), fractions 1–29, containing proteins >150 kDa, did not contain significant amounts of CRS2.