Rabbit antibodies to nucleoli of Novikoff hepatoma and normal liver of the rat.

Antinucleolar antisera were produced in rabbits immunized with whole isolated nucleoli from normal rat liver and rat Novikoff hepatoma ascites cells. These antisera produced positive nucleolar fluorescence of varying degrees in nucleoli and nuclei of Novikoff tumor, rat liver, kidney, and Walker tumor cells. Novikoff hepatoma and liver antinucleolar antisera fixed complement when combined with 0.15 M NaCl-soluble proteins extracted from the hepatoma and liver nucleoli. Nucleolar specificity of the antibodies was demon strated by inhibition of fluorescence or complement-fixation following pretreatment of the immune sera with whole nucleoli or nucleolar 0.15 M NaCl-soluble protein fractions.