FIG. 2.

Fractionation of the activating factors. Concentrated conditioned medium prepared from cells grown in M9 salts plus 1.5% Casamino Acids was fractionated by gel filtration on a Sephadex G-10 column as described in Materials and Methods. Fractions between the void volume and the elution of salts (fractions 12 to 22) were tested for activation of each cma fusion. Fractions 0 to 11 displayed no activity. The same column fraction was used at a concentration of 0.33× in LB to assay each cma fusion. The relative activation values reflect the β-galactosidase activity in each fraction versus the activity in control medium without factor.