Study of Colloidal Gold Strip in Detecting the Antibody of Porcine Epidemic Diarrhea

Abstract

Porcine Epidemic Diarrhea Virus (PEDV) infection has caused huge economic losses, but no serological method is available for batch detection of field samples. The aim of the study was to develop a method for large-batch detection of PEDV infection. Colloidal gold-labeled staphylococcal protein A (SPA) was sprayed on glass fibers to prepare a conjugate pad. The recombinant N protein of PEDV was blotted on the test line of the nitrocellulose (NC) membrane, and pig IgG was streaked on the control line of the NC membrane. The immunochromatographic strip was used for detection of antibodies against PEDV. The results showed that the strip test was simple and the results could be determined within 10 min with naked eyes. The test strip was highly specific for pig serum against PEDV and no cross-reaction was observed. The test strip had close similarity with ELISA. Storage at room temperature for 6 months did not affect the specificity and sensitivity obviously. A total of 320 clinical pig sera were detected by both ELISA and the developed test strip, and the coincidence was 96.3 %. Therefore, the developed immunochromatographic strip is specific, sensitive, stable, fast and simple, and it is suitable for on-site detection of antibodies against PEDV.