Low molecular weight iron in guinea pig reticulocytes

The low molecular weight iron found in the guinea pig reticulocyte has been partially characterized. On thin layer chromatography it is distinguishable from the iron complexes of a variety of nucleotides, sugars, and amino acids. On paper chromatography it comigrates with a 250‐nm absorbing, orcinol‐positive material. The eluted count peak contains phosphorus. Approximately 1 μg of iron is recovered from 1 ml of hemolyzed red cells. Preparation under nitrogen improves recovery of low molecular weight iron, suggesting that the iron is in the ferrous oxidation state.