Estradiol-induced synthesis of vitellogenin. I. The isolation of large polysomes from estrogenized rooster liver.

Conventional procedures for the isolation of polysomes, applied to estrogenized rooster liver, fail to yield polysomes containing 30 or more ribosomes, the size expected for polysomes synthesizing the estradiol-induced protein vitellogenin. A new procedure characterized by early and selective removal of cell components ribonucleases allowed the isolation of polysomes with up to 55 ribosomes. Electron microscopy was used for the determination of polysome size and showed that the large polysomes were not aggregates.