Northern blot analysis of MIGR1-Sox4 clones during myeloid differentiation. Single-cell-derived 32Dwt18 clones (Sox4 A-C, MIGR1 A-C, and Bcr-abl A-B) and wild-type 32Dwt18 cells were treated to differentiate in the presence of Epo (6 U/mL). Cultures were harvested from prior to differentiation treatment (day 0) or at days 3 and 6 following placement in media containing Epo and lacking IL-3. RNA was extracted from cells using RNAeasy (Qiagen). Total RNA (10 μg) was separated on a formaldehyde agarose gel, transferred to nylon membrane, and sequentially probed with murine lactoferrin (mlf) and β-actin.