1. M. R. Clark, Senescence of Red Blood Cells, Progress and Problems. Physiol. Rev. 68:503 (1988).
2. E. Beutler, Isolation of the aged, Blood Cells 14:1 (1988).
3. M. Morrison, C. W. Jackson, T. J. Mueller, T. Huang, M. E. Docktor, W. W. S. Walker, J. A. Singer, and H. H. Edwards, Does red cell density-correlate with red cell age, Biomed. Biochim. Acta 42:107 (1983).
4. M. R. Clark, L. Corash, and R. H. Jensen, Density distribution of aging, transfused human red cells, Blood 74:217A (1989).
5. G. L. Dale and S. L. Norenberg, Density fractionation of rabbit erythrocytes results in only a slight enrichment for aged cells, Biochim. Biophys Acta, in press (1990).