Development And Application Of A Colloidal Gold Immunochromatographic Assay For Detection Of Muskmelon Bacterial Leaf Spot Blight

Bacterial spot of melon leaves caused by Pseudomonas syringae pv.lachrymans is distributed worldwidely and inflicts different degrees of damage.Pseudomona syringa pv.lachrymans has become great threat to cucumber and melon industry.Bacterial fruit blotch is the most important melon seed-borne disease,the pathogen is Acidovorax citrulli,which is a worldwide quarantined disease.Melon infected Acidovorax citrulli and Pseudomonas syringae pv.lachrymans,the symptoms are very similar to each other.It is difficult to use traditional methods distincting between the two.For this reason,ensuring the exclusion of infested seeds by applying the effective,commercially viable and convenient detecting technologies is crucial for the food industry.The research method was using intraperitoneal immunization immunized mice.The cell fusion technique to obtain hybridoma cell lines producing monoclonal antibodies was successful.Additionally,double antibody sandwich model using two different monoclonal antibody preparation of immunochromatographic strip was achieved.An anti muskmelon bacterial leaf spot blight monoclonal antibody(b)fixed to nitrocellulose membrane in the detection area and another kind of anti muskmelon bacterial leaf spot blight monoclonal antibody(c)coupled to colloidal gold particles as chromogenic agent.Subsequently the plant sample solution by capillary action reaction with anti muskmelon bacterial leaf spot blight antibody was added to the detection area,the muskmelon bacterial leaf spot blight retention in the detection area which appeared red gave positive results.In qualitative detection,the detection limit of muskmelon bacterial was determined as 2.5 X 103cfu/mL.Specificity results showed that this strip was no cross-reactivity with Acidovorax citrulli,and had very strong specificity.In the quantitative detection,the detection results were scanned by a membrane strip reader,a standard inhibition curve and calibration curve were established,the regression equation was y=0.3922x-1.2638,R2=0.9881.Therefor,the developed double antibody sandwich colloidal goldstrip is anaccurate,rapid,simple and economical detection method for muskmelon bacterial and applied in the field for the actual samples.