Effect of synthetic peptides on adhesion of erythroid progenitors to 30-/35-kD heparin binding fragments of FN. Bone marrow cells were incubated in wells coated with untreated (□) or heparin-treated (▪) 30-/35-kD fragments, in the absence or presence of 1 mmol/L CS-I, CS-2, CS-3, or PREDVDY synthetic peptides (see Fig 1B). The unattached and attached populations of cells were then assayed for primitive BFU-E (A), mature BFU-E (B), and CFU-E (C). Results are expressed as the mean percent cell adhesion ± SEM (n ≥ 2), * P ≤ .05.