Candidate anti-ID antibodies were sequenced by V-region RT-PCR sequencing. Then recombinant expression constructs were created for the heavy and light chain by gene synthesis. This was followed by recombinant expression in CHO cells via transient plasmid transfection using the ExpiCHO Expression system (ThermoFisher, A29133). Finally, the cell culture supernatants were purified over a Protein A column.