[Establishment of a colloid gold-immunochromatography assay for detection of type Asia I foot-and-mouth disease virus].

Aim To establish a colloid gold-immunochromatography assay (GICA) for detecting type Asia I foot-and-mouth disease virus (FMDV). Methods Colloidal gold was obtained by reducing the gold chloride with sodium citrate and then it was coupled with the purified anti-FMDV type Asia I antibody.The purified anti-FMDV type Asia I antibody and the goat anti-Guinea pig IgG were wrapped onto the nitrocellulose membrane as test line (T line) and control line (C line). The GICA strip was assembled with the purified antibody labelled with colloidal gold and the nitrocellulose containing antibody. The sensitivity, specificity and stability of GICA strip were evaluated in the diagnosis of FMD viral antigen from clinical samples. Results The strip was highly sensitive to FMDV type Asia I(0.116 mg/L) and it had the same result for positive specimens tested thrice. Cross tests proved no cross reaction was found with other serotype FMDV and Swine vesicular disease (SVD) antigen.The corresponding rate of GICA with RIHA was 96.87% for detecting the field sample. The stably test found the strip could be stored for 12 months. Conclusion The GICA strip is a simple and rapid immunochromatographic test strip for the detection of FMDV type Asia I with high sensitivity and specificity.