# Generation of human antibody fragments recognizing distinct epitopes of the nucleocapsid (N) SARS-CoV protein using a phage display approach

## TL;DR

This study generates human antibody fragments that recognize different parts of the SARS-CoV nucleocapsid protein, useful for detection and research.

## Contribution

The novel contribution is the isolation of human scFv antibodies targeting distinct epitopes of the SARS-CoV N protein using a phage display approach.

## Key findings

- Human scFv antibodies were successfully isolated from the ETH-2 phage library against the SARS-CoV N protein.
- The selected scFvs recognize distinct epitopes in the N protein domains and detect SARS-CoV particles in infected cells.
- These antibodies are effective for rapid detection of the N protein in ELISA, western blotting, and immunocytochemistry.

## Abstract

Severe acute respiratory syndrome (SARS)-CoV is a newly emerging virus that causes SARS with high mortality rate in infected people. Successful control of the global SARS epidemic will require rapid and sensitive diagnostic tests to monitor its spread, as well as, the development of vaccines and new antiviral compounds including neutralizing antibodies that effectively prevent or treat this disease.

The human synthetic single-chain fragment variable (scFv) ETH-2 phage antibody library was used for the isolation of scFvs against the nucleocapsid (N) protein of SARS-CoV using a bio panning-based strategy. The selected scFvs were characterized under genetics-molecular aspects and for SARS-CoV N protein detection in ELISA, western blotting and immunocytochemistry.

Human scFv antibodies to N protein of SARS-CoV can be easily isolated by selecting the ETH-2 phage library on immunotubes coated with antigen. These in vitro selected human scFvs specifically recognize in ELISA and western blotting studies distinct epitopes in N protein domains and detect in immunohistochemistry investigations SARS-CoV particles in infected Vero cells.

The human scFv antibodies isolated and described in this study represent useful reagents for rapid detection of N SARS-CoV protein and SARS virus particles in infected target cells.