TBSV IgG–ovalbumin conjugate was diluted in 0.02 M sodium phosphate buffer, (pH8.0) containing 1% sucrose to a final concentration of 2 mg/mL and applied as a 0.5 mm thick, 26 cm line, centrally at 1.25 cm from the top and bottom ends on one side of a 2.5 × 26 cm