TABLE 1.

Troubleshooting table.

Step	Problem	Possible reason	Solution
12	The electrospinning polymer stream ceases	Polymer is collecting and drying at the tip of the needle	Use a paper towel or swab to wipe the collecting polymer away from the tip
	The stream begins to show unusual behavior, i.e., spitting and waving uncontrollably	There is either too much or too little static charge at the tip of the needle	Adjust the voltage knob on the power supply, contacting the needle until a consistent stream is visible. Also, make sure that the aluminum sheet is making contact with the needle and that the wire brush is making contact with the rotating collector. If the problem persists, adjust the tip-to-collector distance from 25 cm
	The tip of the syringe dispenses the polymer in ‘pulses’ or ‘globs’ of large droplets at the collector, instead of in a steady, smooth stream	The solution is too viscous, the feed rate is too low, the setting for the rate of the syringe pump is too high, or there is a bad connection between the power supply and the syringe	Set the syringe pump at a lower feed rate or adjust the diameter settings on the syringe pump to match that of the syringe
17	Fibers are too hydrophobic and are difficult to coat with poly-L-lysine	There are too many fibers on the coverslip	Ensure that during fiber deposition onto the glass coverslips, an interfiber distance of 10–15 μm is maintained
27	Tissue appears sticky and does not disperse when shaken	Dissection took too long	Dissection should take <1.5 h
		No DNase I was added	Make sure to add DNase I at Step 26 of the PROCEDURE
34	Cell pellet is very small	Cells were accidentally removed during the trituration and treatment with Lo-ovo and Hi-ovo solution (Steps 31–33)	Watch the pipette tip during supernatant removal, and ensure that cellular matter is not removed as well
		Too much cellular debris is generated during trituration	Pipette up and down gently during trituration
37	Very few OPCs are attached to the O4 plate	Cells are lost during transfer between immunopanning plates	Ensure that all liquid is transferred between immunopanning plates
39	Low OPC yield	Cell pellet may have been lost during supernatant removal at Steps 34 and 39	Carefully decant supernatant next time
42	Slow OPC differentiation	The number of viable OPCs in the culture might be low resulting in OPC proliferation rather than differentiation	Gentle manipulation of culture dishes and cell dissociation techniques need to be employed to ensure viability of purified OPCs (one has to perform another OPC preparation applying gentle techniques, as no parts of the steps can be repeated within the same preparation)
48	OPCs are found in the space between fibers rather than interacting with fibers	Evaporation after fiber fabrication occurs too quickly, creating fibers that are nonporous	Ensure a higher ambient humidity during electrospinning
		There are too few fibers on the coverslip	Ensure that fibers fill >50% of the coverslip surface area with a distance of 10–15 μm between fibers
	It is difficult to visualize distinct myelin-like segments because of fiber density	There are too many fibers on the glass coverslip	Ensure 10–15 μm of distance between fibers during fiber deposition onto the coverslip