FIG. 1.

Binding of soluble fibronectin to L. monocytogenes. Intact L. monocytogenes 90/636 cells were immobilized on a microtiter plate and incubated with increasing concentrations of fibronectin. After washings, bacterial attachment of fibronectin was quantitated spectrophotometrically by an ELISA with peroxidase-labelled rabbit anti-human fibronectin Ig and tetramethylbenzidine as the substrate. Each square represents the average of three separate determinations after subtraction of the background value (0.082) obtained in the absence of added fibronectin. Blank values obtained when similar experiments were done in the absence of L. monocytogenes cells were lower than 0.06 optical density (OD) unit. Standard errors not comprised within squares are indicated by bars.