A significant number of biopharmaceutical groups are looking to develop therapeutic antibodies, antibody-like molecules or fragments against cell surface antigens. To improve the reliability of hits, it is beneficial to screen against cell lines expressing the antigen of interest rather than immobilised purified antigen. The advantage of the cellular approach is that antigen epitopes are more likely to be preserved in their natural confirmation and therefore the incidence of false positive, or negative binding events should decrease. However, when cells die their membranes can become ruptured and expose a large range of proteins, which can lead to significant off-target antibody binding. A further concern is that the target protein may undergo degradation during apoptosis, which could lead to lower apparent binding levels through loss of epitope integrity. By simply eliminating dead cells from analysis, the quality of screening data can be further enhanced.