Ag85 detection limits in a sandwich assay.

<p>10⁶ yeast displaying the indicated antibodies were induced, washed and resuspended in serial antigen dilutions. Binding was detected by flow cytometry following the addition of the indicated scFv-Fc fusion antibodies as induced culture supernatants, and fluorescent anti-rabbit secondary reagents. The indicated detection limits are defined as the minimal antigen concentration giving a signal three times greater than background. A: Detection in phosphate buffered saline. B: Detection in 1∶50 human serum diluted in PBS.