Table 2.

Advantages and limitations of different methods of exogenous DNA transfer. Single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA)

Category	Method	Advantages	Limitations
Transformation	Natural	Deliver as ssDNA and technically simple	Necessary genes only possessed by a small number of bacteria
	Chemical	High transfer efficiency and technically simple	Delivered as dsDNA and may lyse recipient cell membrane
	Electroporation	High transfer efficiency	Delivered as dsDNA and may lyse recipient cell membrane
	Biolistic	Novel	Delivered as dsDNA and requires expensive equipment
	Sonoporation	High transfer efficiency	Delivered as dsDNA
	Tribos	Novel and technically simple	Delivered as dsDNA
Conjugation	Conjugative transposons	Delivered as ssDNA and wide host range	Cell numbers cannot be recovered prior to chromosomal insertion, often have preferred insertion sites
	Suicide plasmid vectors	Delivered as ssDNA and easily customised in well characterised donor	Cell numbers cannot be recovered prior to chromosomal insertion
	Shuttle vectors	Delivered as ssDNA, easily customised in well characterised donor and transconjugant population recoverable	Can be difficult to eliminate from bacteria once established
Transduction		Very high transfer efficiency	Establishing for a new strain is very time consuming