Table 1.

A panel of commonly used affinity tags selected for purification of recombinant fusion proteins and their associated characteristics.

Tag	Size [amino acids or kDa]	Ligand or separation method	Referencea
Polyhistidine	5–15 a.a.	IMAC	[6]
HA-tag	9 a.a.	mAb based	[7]
FLAG	8 a.a.	mAb based	[8]
Strep tag I	9 a.a.	Streptavidin	[9]
Strep tag II	8 a.a.	Streptactin	[10]
Softag 1	13 a.a.	mAb based	[11]
Softag 3	8 a.a.	mAb based	[12]
T7-tag	11–16	mAb based	[13]
c-myc	10 a.a.	mAb based	[14]
S-peptide	15 a.a.	S-protein	[15]
Polyaspartic acid	5–16 a.a.	Ion-exchange or precipitation	[16]
VSV tag	11 a.a.	mAb based	[17]
Calmodulin binding peptide	26 a.a.	Calmodulin	[18]
Glutathione S-transferase	26 kDa	Glutathione	[19]
Maltose binding domain	40 kDa	Maltose, amylose	[20]
PinPoint (Promega)	13 kDa	Streptavidin/avidin	[21]
Cellulose binding domain (Novagen)	27–189 a.a.	Cellulose	[14]
Xylanase 10A	163 a.a.	Cellulose	[22]

^aOnly one relevant reference is given.