FIG. 4.

Assessment of bacterial binding using SPR technology. (a) Association/dissociation sensorgrams obtained for 10⁶-CFU/ml suspensions of E. coli using chips coated with K₁₅ (dashed and dotted line), K-7α₁₂ (dashed line; full-scale sensorgram is shown below), and protected K-7α₁₂ (solid line). (b) Dose dependence of E. coli binding to K-7α₁₂-coated chip for suspensions containing 10², 10³, 10⁴, 10⁵ (solid lines, form bottom to top), and 10⁶ (dashed line) CFU/ml, displaying increasing response signals. Note that control experiments (bacteria injected over noncoated chip or saline injected over OAK or K₁₅ chips) yielded a negligible resonance signal. (c) CFU counts obtained from collecting and plating each run shown in panel b. Error bars represent standard deviations from the means. An absence of bars indicates reproducibility.