FIG. 2.

Histogram representation of the results of colorimetric assays for determining the accessibility and IgG-binding capacity of affibodies displayed on cell surfaces. (A) Results for detection of the accessibility of receptors displayed on the cell surface and containing regions with albumin-binding capacity. Wild-type and recombinant S. carnosus cells were incubated with biotinylated HSA for binding to successfully exposed receptors containing ABP. Streptavidin-alkaline phosphatase conjugate was added, and absorbance at 405 nm was monitored after addition of substrate. (B) Results for detection of IgG-binding capacity by using biotinylated IgG in an assay similar to that used for panel A. Wild-type cells (Sc:wt) were used together with pSCXm-transformed S. carnosus cells (Sc:m) as controls in all experiments. OD, optical density.