Patent ID: 7855275

Claim:
A cysteine engineered antibody comprising a free cysteine amino acid having a thiol reactivity value in the range of 0.6 to 1.0; and a sequence in the light chain selected from SEQ ID NOS: 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 45, and 46: SLSASCGDRVT (SEQ ID NO: 17) QKPGKCPKLLI (SEQ ID NO: 18) EIKRTCAAPSV (SEQ ID NO: 19) TCAAPCVFIFPP (SEQ ID NO: 20) FIFPPCDEQLK (SEQ ID NO: 21) DEQLKCGTASV (SEQ ID NO: 22) FYPRECKVQWK (SEQ ID NO: 23) WKVDNCLQSGN (SEQ ID NO: 24) ALQSGCSQESV (SEQ ID NO: 25) VTEQDCKDSTY (SEQ ID NO: 26) GLSSPCTKSFN (SEQ ID NO: 27) FLSVSCGGRVT (SEQ ID NO: 45) QKPGNCPRLLI (SEQ ID NO: 46) where the cysteine in SEQ ID NOS: 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 45, and 46 are the free cysteine amino acid.