Regulatory guidelines require testing for bioprocess impurities. Reduction of bioprocess impurities to the lowest levels practical calls for sensitive and robust analytical methods. Cygnus offers a full menu of HCP ELISA kits and orthogonal testing services for all current cell expression systems utilized for viral vector manufacturing, ELISA for residual BSA and EndonucleaseGTP®, and viral clearance kits. Orthogonal HCP analytical methods include Antibody Affinity Extraction™ (AAE™), Mass Spectrometry and 2D PAGE. The integration of data from these orthogonal methods together with ELISA data provides a comprehensive analysis of HCP content, that will meet regulatory expectations.