ELISA microplate: a viable immunocapture platform over magnetic beads for immunoaffinity-LC–MS/MS quantitation of protein therapeutics?

Aim: Evaluate the performance of ELISA microplates versus commonly used magnetic beads for biological sample cleanup and/or enrichment in immunoaffinity-LC–MS/MS to reduce tedious beads washing procedures and a relatively high assay cost. Materials & Methods: ELISA microplates were used as immunicapture platform and compared with magnetic beads for sample cleanup for LC–MS/MS quantitation of protein therapeutics. Results: One unmodified and two surface-activated microplates provided comparable linear ranges and sensitivities for a therapeutic protein (mass 78 kDa) using a human serum sample of 100 µl with 1:1 dilution compared with Tosylactivated magnetic beads using 200 µl of human serum without sample...