Figure 1.

Schematic description of artificial fouling of MabSelect SuRe resin in PreDictor plates. Steps 1, 3 and 5 show equilibration or wash with PBS (20 mM phosphate, 0.15 M NaCl, pH 7.4). In step 2, which was repeated four times, E. coli lysate spiked with polyclonal IgG was added to the resin and incubation was done for 45 min. In step 4, a fouling agent composed of 2.9 M ammonium sulfate, 0.6 M phosphoric acid, pH 2.5 was added, followed by incubation overnight in order to accelerate the fouling of the resin. After a subsequent wash, the bound IgG was eluted with 0.1 M sodium citrate pH 3.0. The resin in the wells was mixed at every step and liquid was removed by centrifugation between each step. H₂O, ultrapure water.