Specificity of the strip test. Culture supernatants containing the seven serotypes of FMDV (50 μl) was mixed with 1 μl of biotinylated capture mAbs (F1O-2-5 for serotype O, F66A22-14 for serotype A and F34Asia-8, F36Asia-14 for serotype Asia 1) and 6 μl of colloidal-gold conjugated F21-140SO in the running buffer (50 μl). The mixture (100 μl) was applied to the gRAD. After 10 minutes, the result was recorded. T is the test line and C is the control line. (a). The LFI strip test for serotype O; (b). for serotype A and (c). for serotype Asia 1.