FIG 3.

Screening and identification of the nanobodies against the PRRSV-N protein. (A) Identification of the periplasmic extracts from the 96 clones specifically binding to the PRRSV-N protein using iELISA. The 36 clones were positive. (B) Amino acid sequence alignment of three nanobodies against PRRSV-N protein with human VH. The hallmark residues at positions 37, 44, 45, and 47 are highlighted with a red box. (C) Three nanobodies specifically reacted with the PRRSV-N protein using the iELISA. The recombinant NDV-NP protein was used as a negative control. (D) Titration of the nanobodies binding with the PRRSV-N protein in the periplasmic extracts.