Fig. 2

Screening nanobodies against PCV2-Cap protein. a Titer of antibody against PCV2-Cap protein in the serum from the immunized camel. b Detection of specific phage enrichment with ELISA. c Alignment of amino acid sequence of 19 screened nanobodies. The residues at positions 37, 44, 45, and 47 are indicated by red triangles. d Specific reactions between the 10 screened nanobodies and PCV2-Cap protein. TGEV-S protein was used as a His-tag control protein. e Titration of the 10 screened nanobodies binding with the PCV2-Cap protein. Nb91, a screened negative nanobody was used as negative control