Division 1 Solutions and materials required:F1F2

40 ml of 1,6 % agarose in 0,05 M Tris/HCl buffer, pH 7,2 with 8,5 % NaCl;

15 ml of a bovine leukosis serum, having antibody only to bovine leukosis virus glycoproteins, diluted 1:10 in 0,05 M Tris/HCl buffer, pH 7,2 with 8,5 % NaCl;

15 ml of a bovine leukosis serum, having antibody only to bovine leukosis virus glycoproteins, diluted 1:5 in 0,05 M Tris/HCl buffer, pH 7,2 with 8,5 % NaCl;

four plastic petri dishes with a diameter of 85 mm;

a punch with a diameter of 4 to 6 mm;

a reference antigen;

the antigen which is to be standardised;

a water bath (56 °C).