A rapid method for the fractionation of avian blood cell nuclei

Summary Red blood cell nuclei from avian anaemic blood have been fractionated by rate sedimentation on discontinous sucrose gradients into fractions which can be distinguished both by their RNA synthesizing ability and by their morphology as revealed by electron microscopy.Acknowledgment. We wish to thank H. Gitay for the electron micrographs. This work was supported by grants from the University of Cape Town Research Committee and the Council for Scientific and Industrial Research.