Abstract
Serum transferrins have been examined in 392 samples from full-term infants and from premature infants at various stages of growth. The characteristic transferrin pattern of the infants by starch gel electrophoresis contained a single prominent iron-binding component accompanied by 4 faint, slower migrating components. An additional faint component was present in the sera of infants heterozygous for a transferrin variant. The faint components migrated slightly more rapidly than the corresponding components in the stepwise pattern produced by the action of neuraminidase in removing sialic acid from transferrin. The interpretation is presented that the faint components may represent the absence of multi-unit carbohydrate prosthetic groups on the transferrin molecule in the infant. A similar interpretation is possible for the slow migrating transferrins of cerebrospinal fluid.