SUMMARY

The production, purification and properties of the 'A ' antigen induced by Marek's disease virus in tissue culture were investigated. It was found that although virus multiplied on passage in chick kidney, chick embryo and duck embryo cells the antigen was produced only in chick kidney and duck embryo cultures. The results uggested that the 'A ' antigen produced by duck embryo cells was a glyco-protein having a mol.wt, in the range 7o ooo to 9o ooo and was heterogeneous in charge (pI 4"5 to 5"5)- A 2o-fold purification was achieved by electrophoresis in 5 ~o acrylamide gel with a recovery of 45 ~. An equally good purification was also possible by chromatography on DEAE-Sephadex A5o and Sephadex G2oo, although the recovery was only 20 ~o in this case