Generation of glycoengineered FcαRI BsAbs by Fab-arm exchange. Sandwich ELISA showing successful Fab-arm exchange indicating that glycoengineered FcαRI BsAbs (light gray) can bind equally as the glycoengineered parental forms ie anti-EGFR (black) and anti-FcαRI (dark grey). (A–D) Both coating and detection of anti-EGFR with anti G1m(f) allotype specific antibodies shows that anti-EGFR WT and glycoengineered parentals could be detected. (E–H) Coating and detection of anti-FcαRI with anti G1m(a) specific antibodies shows that anti-FcαRI WT and glycoengineered parentals were detected. (I–L) When G1m(f) (anti-EGFR arm) was used for coating and G1m(a) (anti-FcαRI arm) for detection, only WT and glycoengineered FcαRI BsAbs were detected. Data show mean ± standard deviations (SD) of 450 nm to 500nm. OD, optical density.