Four hybridoma clones which produce monoclonal antibodies against chick embryo DNA polymerase alpha have been established. Antibodies produced by the four clones all belonged to the gamma 1-type IgG and precipitated enzyme activity in the presence of Staphylococcus aureus cells. An affinity column prepared with one of the monoclonal antibodies (clone 6-1E) and protein A-Sepharose retained DNA polymerase alpha activity as well as the 135,000 approximately 150,000 and 50,000 approximately 60,000 dalton polypeptides of this enzyme. Thus, the antibody is specific to DNA polymerase alpha.