Table 1.

Examples chemical modifications and effects on various oligonucleotide properties.

Modification		Nuclease Resistance	Polymerase Compatibility	Duplex Stability	Watson–Crick Base Pairing	Ref.
Sugar	2′-F	Increase	Yes	Increase	Yes	[17,18]
	2′-OMe	Increase	Yes	Increase	Yes	[17,18]
	2′-NH2	Increase	Yes	Decrease	Yes	[17,18]
	LNA	Increase	Yes	Increase	Yes	[18,19]
	HNA	Increase	Yes	Increase	Yes	[12]
Phosphodiester Linkage	triazole-linked	Increase	No	Decrease	N/A	[20]
	PS	Increase	Yes	Decrease	N/A	[21,22]
	phNA	Increase	Yes	Decrease	N/A	[23]
Base	7-deaza-dA	Increase	Yes	Decrease	No	[24]
	Z/P	Unreported	Yes	Increase	Yes (modified)	[25]
	Ds/Px	Unchanged	Yes	Increase	No	[26]
	5-isobutyl-carboxamide-dU	Unreported	Yes	Increase	No	[27]