The invention relates to a method performed ex vivo for removal of tumor cells from intraoperatively collected blood salvage, to antibodies and scaffold proteins which mimic antibodies for use in said ex vivo method, to the use of said ex vivo method for removal of tumor cells from intraoperatively collected blood salvage followed by reintroducing the so obtained purified blood salvage or of concentrates of erythrocytes purified by said method to a patient from whom said intra-operatively collected blood was obtained, as well as to blood salvage or a concentrate of erythrocytes, both obtainable by said method for reinfusion to said patient.