Table 1.

Reagents Used in Magnetic-Activated Cell Sorting of T Cell Receptor-Engineered T Cells^a

Sort reagent	Label	Second step sort reagent	TCR transgenes	Concentrationb(ng/107 T cells)	pMHC valency	Detachable binding	Key reference(s)
gp 100/A2 tetramerc	R-Phycoerythrin	Anti-PE microbeads	TCRαβ	700	4	No	Altman et al., 1996
gp 100/A2 pentamerd	R-Phycoerythrin	Anti-PE microbeads	TCRαβ	500	5	No	Sebestyén et al., 2008
gp 100/A2 Streptamere	R-Phycoerythrin	Anti-PE microbeads	TCRαβ	200	8–12	Yesf	Knabel et al., 2002
							Neudorfer et al., 2007
CD34 mAb microbeadsg	—	—	TCR-tCD34	ND	None	No	Stull et al., 2000

^aAn overview of specific characteristics of various sort reagents to enrich TCR-engineered T cells is shown.

^bConcentrations of peptide–MHC multimers are based on molecular weight provided by manufacturers.

^cTetramers contain four biotinylated peptide–MHC monomers, which are multimerized with Streptavidin–PE to form a tetrahedral complex. A maximum of three peptide–MHC molecules is available per focal plane (Yao et al., 2008).

^dPentamers contain five peptide–MHC–PE monomers, which are multimerized through a coiled-coil structure. All five peptide–MHC molecules are available per focal plane (Yao et al., 2008).

^eStreptamers contain between 8 and 12 Strep-tagged peptide–MHC monomers, which are multimerized with Streptactin–PE.

^fRelease of peptide–MHC monomers is established by addition of an excess of d-biotin that has a high affinity for streptactin (K_d, ∼10–13 M) (Neudorfer et al., 2007).

^gCD34 mAb is directly coupled to magnetic microbeads.

mAb, monoclonal antibody; ND, not determined; PE, phycoerythrin; pMHC, peptide–MHC; tCD34, truncated CD34; TCR, T cell receptor.