Selection of transplant immunome displaying scFv phage libraries on myeloma cells. (A) Schematic diagram illustrating the strategy to clone patients’ B-cell immune repertoires into the pHAL14 scFv phage display vector. (B) Proof-of-principle selection of healthy donor scFv phage library spiked with 0.1% anti-CD71 scFv phage on CD71⁺ cells. (C) Deep-sequencing–assisted screening of patient-derived transplant immunome scFv phage libraries on myeloma cell lines. Graphs display heavy-chain CDR3 clonal dynamics of the most frequent clones during selection rounds. Smaller clones are summarized in gray. (D) Flow cytometry–binding analysis of scFv phage clone CARRSDAFDIW derived from transplant immunome library 4 on myeloma cell line (EJM) and control cell line (Jurkat). VH, heavy chain variable region; VL, light chain variable region.