Construction and characterization of a novel recombinant single-chain variable fragment antibody against White Spot Syndrome Virus from shrimp.

An antibody phage display library against White Spot Syndrome Virus (WSSV) was constructed. After four rounds of panning against WSSV, 192 out of 480 clones displayed WSSV binding activity. One of the positive clones, designated A1, had relatively higher activity specifically binding to WSSV. A1-soluble, single-chain fragment variable (scFv) antibody has an affinity constant (K(aff)) of 2.02+/-0.42x10(9) M(-1). Dot blot assays showed that A1-soluble scFv could detect WSSV directly from shrimp hemolymph after 24-h feeding infection by WSSV. A1 scFv has potential for the development of a cheap, simple and sensitive diagnostic kit for WSSV in the field.