Shake flask experiments for screening of permeabilization agents for their ability to selectively release periplasmic proteins: (A) AP assay indicating periplasmic release for shake flask experiment 1; (B) β‐galactosidase assay indication cell lysis for shake flask experiment 1; 1, no addition of agent; 2, TRIS 200 mM; 3, TRIS 300 mM; 4, TRIS 500 mM; 5, guanidine HCl 2 M; 6, Triton 0.5%; 7, 200 mM guanidine HCl + 0.5% Triton; 8, urea 2 M; 9, benzalkonium chloride 150 mg/L; (C) AP assay indicating periplasmic release for shake flask experiment 2; and (D) β‐galactosidase assay indication cell lysis for shake flask experiment 1; 1, no addition of agent; 2, 250 mM TRIS; 3, 300 mM TRIS; 4, 350 mM TRIS.