Development of an ELISA-LC-MS hybrid assay for quantification of biotherapeutics

Background: Magnetic bead immunocapture-LC-MS has been widely used for bioanalysis of biotherapeutic proteins. However, magnetic beads are difficult to be fully automated and more costly than ELISA plates. Aim: Develop an ELISA-LC-MS hybrid assay as an alternate platform. Results: Among seven ELISA plates tested, Pierce streptavidin plates, which did not require time-consuming capture antibody precoating steps, provided the best sensitivity and assay dynamic range (5-2500 ng/ml or 10-5000 ng/ml), similar to magnetic bead immunocapture-LC-MS assay and better than an ELISA (50-500 ng/ml). The entire procedures could be fully automated using a liquid handling system. Conclusion: This study demonstrates that ELISA-LC-MS hybrid approach using streptavidin plates represents a promising platform for bioanalysis of biotherapeutics.