FIG. 2.

Determination of in vivo levels of σ³². Relative levels of cellular σ³² were determined by Western blotting using polyclonal anti-σ³² antibodies as described in Materials and Methods. The position of the σ³² band is indicated with an arrow, and the band used as an internal standard (to correct for protein loading) is labeled with an asterisk. The identities of the σ³² substitutions are indicated above the lanes. In the control lane, an extract was loaded from a cell not containing a σ³² expression plasmid.