E. coli HCP 2G Assay Reagent Set for Gyrolab® is designed for determining the presence of host cell protein contamination in products manufactured by expression in E. coli strains. This Reagent Set should be used in conjunction with a Gyrolab® Bioaffy™ 1000 HC Assay Toolbox available from Gyros Protein Technologies. This simple to use, high throughput, and semi-quantitative assay is a method to aid in optimal purification process development, process control, routine quality control and product lot release. It is derived from the same antibodies and antigen used in the Cygnus 2nd generation E. coli HCP ELISA Kit, Cat# F1020. The reagents are "generic” in the sense that they are intended to react with essentially all the host cell proteins (HCPs) that could contaminate the product independent of the purification process. The antibodies have been generated in goats and antigen affinity purified using E. coli HCPs found in mild lysate from a number of widely used E. coli strains. The combination of the Reagent Set and Bioaffy 1000 HC Assay Toolbox is optimized for use in Gyrolab automated immunoassay systems enabling generation of 96 data points in 75 minutes without manual intervention. The results are evaluated using Gyrolab Evaluator software.