Fig. 4.

Maintenance of OPCs in culture and recognizing contaminating cell types A. PDL coating of cell culture dishes is critical for the adherence of OPCs. If the PDL coating is suboptimal, or cell culture substrates are not dried at this step, OPCs may fail to attach to the plates and subsequently form spheres, as seen here. B. In certain cases, contaminating cell types may be present in these cultures. In the case illustrated here, cells were maintained for 13 DIV under proliferative conditions but without passaging, and as a result became over-confluent, at which point cells may differentiate into astrocyte-like cells. C. Here as well, contaminating cell types (white arrows) are seen amongst the OPCs (white dashed arrows), which are themselves easily recognizable as small, rounded cells with processes. D. The media used to culture OPCs is serum-free. Inclusion of serums like Fetal Bovine Serum (FBS), such as was done in this example, directs cell fate towards the astrocyte lineage (white arrows), resulting in a mixed cell culture population. Scale bar, 20 µm.