Fig. 2From: A structure and knowledge-based combinatorial approach to engineering universal scFv antibodies against influenza M2 proteinScreening of scFv against the U1 epitope. A In the fourth round of biopanning, approximately 400 individual scFv phages were selected, and the monoclonal phage ELISA was performed. Based on absorbance cutoff (O.D.490 nm= 2.0), 72 high binder scFv phages were selected, and each phage was quantified. B After quantification of scFv phages, we picked phages in equal numbers (1 × 109) to perform the monoclonal phage ELISA. The top 24 scFv phages were selected based on absorbance cutoff (O.D.490 nm = 2.4). C Sequencing of all scFvs revealed only 4 unique clones with sequence diversity in CDRs. Residues highlighted in red color are the same in all scFvs. All experiments were done in triplicate. The error bars represent standard deviationsBack to article page