For this assay, the test sample (0.5 g) was cut into less than 0.25 cm pieces and placed in the bottle of extraction buffer B (4 ml) containing beads for the extrac tion of pathogen proteins. The bottle was shaken for 1 min. Two to three drops of the resulting liquid were put onto the strip using a dropper, and any flooding on the Pocket Diagnostic strip was avoided. Deionized water was used as the negative control in each experiment. If both a test line (red in AgriStrip and blue in Pocket Diagnostic) and control line were observed, the sample was declared fire blight positive. The sample was considered fire blight negative if only the control line was visible after using the sample buffer extract. Test was considered invalid and was repeated with no visible lines. The immunoassay experiments were conducted using two biological replicates