Figure 2.
Interaction between AFM tip and lawns of isogenic E. coli strains differing in LPS composition. (A) Core LPS structure of E. coli K12 strain D21 and its isogenic LPS mutants expressing truncated core LPS molecules. (B) Representative force curves between bare silicon nitride tip and isogenic E. coli mutant strains expressing truncated core LPS molecules in 1 mM Tris (pH 7.5). ▴, D21; ×, D21e7; □, D21e19; ○, D21f1; ▵, D21f2. (C) Representative force curves between bare silicon nitride tip and D21f2 in distilled deionized water, 1 mM Tris, and 1 mM Tris plus 100 mM NaCl. •, D21f2 in water + D21f2 in Tris; □, D21f2 in Tris + NaCl.