Development, Optimization and Validation of a Sandwich ELISA for Detection of Recombinant Human Factor VII

Abstract

Recombinant human factor VII (rh-FVII) is produced by engineered BHK cells at low dose. Accordingly, establishment of a precise method is crucial to reliably measuring expression level of this protein during manufacturing pro-cesses. We developed and established a reproducible sandwich enzyme-linked immunosorbent assay (ELISA) method for measuring amount of FVII during biopharmaceutical in upstream and downstream processes of Aryo-Seven. A sandwich ELISA was designed using two different high affinity mon-oclonal antibodies (mAb1 and mAb2) against h-FVII. The bounded FVII to the first antibody was revealed by the use of a second mouse anti-FVII monoclo-nal antibody (1F1-B11), labeled with HRP that binds to another antigenic determinant of the FVII. Then, validation was done by determination of spec-ificity, linearity, accuracy, precision, reproducibility, detection and quantifica-tion limit and robustness according to ICH Q2 (R1) guideline. In developed ELISA, no interference was found between FVII and proteins derived from BHK which commonly exist in the supernatant. Linear range of detection was from 25-1.56 ng/mL with P-Value <0.001. In accuracy, spiked samples showed 109±2% recovery. Intra and intermediate precision assays showed %RSD not more than20. Detection limit of this assay was 0.99 ng /mL and limit of quantification was 2.99 ng/ml. The sandwich ELISA was found to be useful tool for measuring FVII/ FVIIa. The ELISA approach was precise, repro-ducible, and accurate. The ELISA therefore, is offered as an assured kit for detection of recombinant human factor.