Plate two or three pre-coated 100-millimeter Petri dishes with 10 milliliters of the cell suspension.
Incubate in a humidified incubator at 37 degrees Celsius under 5% carbon dioxide.
In a laminar flow hood under sterile conditions, renew the culture medium with 10 milliliters of warm Mbb 27 low medium.
Incubate for 2 days in a humidified incubator at 37 degrees Celsius under 5% carbon dioxide.
To harvest the OCM, collect the supernatant containing oligodendrocyte-secreted factors. Filter-sterilize the OCM using a 0.22-micron filter.