RED CELL DIAMETERS IN HUMAN CORD AND NEONATAL BLOOD

¹ Physiology Laboratory, University College, Dublin

The fall in mean cell volume and diameter during intrauterine and early extra-uterine life has suggested that ftal cells are larger than adult. Direct measurements of their diameters has been made by differential acid-phosphate elution and the use of an image-splitting microscope [Dyson, 1959]. These show that the mean diameter of ftal cells is significantly lower than that of adult erythrocytes in ftal and neonatal blood, and that the reduction in mean cell volume is accomplished by the disappearance of large cells which, since they contain adult hæmoglobin exclusively, can properly be called adult macrocytes.

Note:

I should like to thank Professor E. F. McCarthy for his advice and assistance in the preparation of this paper, Drs. D. and G. McCarthy, St. Kevin's Hospitals, and C. Saunders and C. Ward, Our Lady's Hospital for Sick Children, for blood samples, Mr. T. P. Linehan, Central Statistics Office, for his analysis of our results, and Mr P. O'Shea whose help was forthcoming at all stages of the work. I am grateful also to Messrs. Cooke, Troughton and Simms, York, through whose courtesy the Dyson image-splitting eyepiece became available.