Table 4.

Four methods for transfecting neurons in primary neuronal cultures. Viability is defined as the proportion of the cells that survive the transfection procedure. Transfection efficiency is defined as the proportion of surviving cells that express the transfected plasmid.

Transfection method	Viability	Transfection efficiency	Advantages	Disadvantages
Electroporation	~ 60–80% (depending on the cell density)	~5–10% for cortical neurons. <1% for DRG neurons in long-term myelinating co-cultures.	Simple and effective. Consistent and moderate expression levels.	Requires an electroporation device. The commercially optimized reagents can be very expensive. Not selective for neurons. Low yield of viable cells.
Lipofection	~40–60% (depending on the cell density and DNA concentration)	<1% for DRG neurons in long-term myelinating co-cultures (typically ~5–10 neurons per culture dish).	Simple and inexpensive. No special equipment required.	Hard to control expression. Low transfection efficiencies. Not selective for neurons.
Magnetofection	~50–70% (depending on the cell density)	~5–10% for cortical neurons.	Simple and inexpensive. Better transfection efficiency than lipofection.	Hard to control expression. Requires a magnetic plate. Not selective for neurons.
Nuclear injection	~80–90% (with a skilled operator)	~70–90% for SCG neurons depending on the culture age. 50% for DRG neurons in long-term myelinating co-cultures.	Works for hard-to-transfect cells. Permits selection of the cells to be transfected.	Labor-intensive. Requires specialized equipment, training and practice.