Dr. Jackie Damen:
To identify lineage differentiation, flow cytometry is typically used after staining with a lineage-specific marker. For human erythrocytes, these would be expected to be positive for both CD71 and GlyA. However, if you are distinguishing different lineages using the the CFU assay, for colonies from myelopoiesis there are 3 main colony types: myeloid (CFU-GM), erythroid (BFU-E and CFU-E), and multi-potential progenitors (CFU-GEMM).
Once the progenitors grow and mature in an optimized formulation of MethoCult™ media, the result is colonies that contain mature cells that differ in size and color. Erythroid progenitors (BFU-E and CFU-E) will consist of small, red colored erythroblast cells at the edges of the colony and are distinctively different (when observed down the 10x objective of an inverted microscope) from myeloid colonies (CFU-GM), which consist of larger, clear and shiny granulocytes, monocytes, and macrophages.
The identity of mature cells within colonies from the various lineage types was confirmed historically using histological hematoxylin and eosin (H&E) staining as well as evaluation of lineage-specific surface marker expression using FACS.
For more, refer to the Atlas of Hematopoietic Colonies from Cord Blood.