The production of therapeutic proteins is at the forefront of the bio-pharmaceutical industry.Because of the superior fidelity of animal cells in producing clinically relevant proteins.The protein therapeutic market was valued in excess of $57 billion in 2006,with monoclonal antibody therapeutics leading the field.However a major bottleneck in both discovery and development of cell lines is finding and isolating the best cell clones from large heterogeneous cell populations.High throughput automation is one option to handle the ever-increasing workload but a better solution is to rapidly find and isolate only the best candidates,thereby eliminating thousands of irrelevant clones before substantial effort and costs have to be invested in selection,growth and maintenance.