Table I.

Binding of threshold ligands to thymocytes from three different TCR transgenic mouse strains (T1, S14, and OT-1 TCR)

TCR /ligand	pMHC monomers		pMHC tetramers
	DP thymocytes (K d [M])	SP thymocytes (K d [M])	SP thymocytes (r 1/2 [M])
T1/4A-Kd	5.4 ± 1.6 × 10−6	5.5 ± 1.8 × 10−6	Not done
T1/4S-Kd	6.1 ± 1.1 × 10−6	7.9 ± 2.0 × 10−6	9.0 ± 1.5 × 10−8
S14/4L-Kd	6.4 ± 1.5 × 10−6	6.2 ± 1.7 × 10−6	8.8 ± 1.6 × 10−8
OT-1/OvaT4-Kb	Not done	Not done	7.6 ± 0.7 × 10−8

Mean values and SEMs of at least three independent experiments are shown.