50 mm of imidazole trace 3 elution 2 with 50 mm of imidazole trace 4 elution 1 with 100 mm of imidazole trace 5 elution 2 with 100 mm of imidazole trace 6 elution 1 with 150 mm of imidazole trace 7 elution 2 with 150 mm of imidazole trace 8 elution 1 with 200 mm of imidazole molecular weights of 70 and 130 kda are noted it is observed that the hemagglutinin h5 seq id no 8 with a molecular weight of 70 kda is obtained at homogeneity with elution with 150 mm of imidazole eliminating dimers and contaminants this makes it possible to work with it for the subsequent conjugation processes chemical conjugation of hemagglutinin h5 seq id no 8 of the avian flu virus with anti dec205 monoclonal antibodies the anti ctld 2 monoclonal antibodies 2f2e8d3b6 at a concentration of 1 mg ml were activated with a 20 u00d7 molar excess of the cross linked agent smcc succinimidyl 4 n maleimidomethyl cyclohexane 1 carboxylate smcc pierce rockford ill usa in pbs with 5 mm of edta for 2 hours at 4 u00b0 c this cross linking agent contains an nhs ester group and a maleimide group that makes possible the covalent conjugation of the molecules that contain the amino groups and sulfhydryl groups respectively after activation the samples were dialyzed against pbs in order to eliminate the reagent that had been released on the other hand the h5 recombinant protein that was obtained in the previous example was modified with 2 iminothiolane traut 39 s reagent pierce rockford ill usa which reacts with primary amines in order to add a sulfhydryl group.