Studies of the distribution of proteins bound to CNBr-activated Sepharose 6B at the electron-microscopic level

Proteins were covalently attached to Sepharose by the CNBr method. Their distribution across the carrier beads was studied at the electron microscopic level. The approach has been to ferritinstain and to section the gel beads. Ferritin was either coupled directly to the polysaccharide backbone of the carrier or conjugated with pure rabbit anti-aminopeptidase in order to visualize covalently bound leucine aminopeptidase by the immunferritin technique. The results corroborate earlier fluorescence microscopic findings of a uniform protein distribution, provided that a number of conditions are fulfilled.