Isolation of Antibody Binders to MISIIR from a Phage Display Library by Sorting

Cell surface antigens represent the most common targets for antibody-based cancer therapy. Isolation of lead antibodies to these membrane targets from antibody repertoires, such as immunized or naïve phage display libraries, has been a challenging task, which is an outstanding issue when soluble portion of the target(s) is not available, and/or a naïve phage display library is used. Common cell-based panning methods often encounter numerous difficulties, including high background and loss of cells during repeated washes. Here we described a novel FACS sorter-based protocol to isolate single-chain Fv molecules specific for defined antigen MSIIR expressed on stably transformed mammalian cells, and screening of unique binders to the tumor target.