In-Cell ELISA Assays to Assess Drug Relative Potency Using the Cytation Imaging Reader for Sample Analysis

Purpose

Potency assays are crucial characterization tools for almost all biotherapeutics during clinical and pre clinical development for quality control and market authorization purposes. These potency assays must be tailored to the drug mechanism of action (MOA) and provide a specific readout related to the drug’s biological properties. Many formats exist for measuring drug potency (i.e. ELISA, flow cytometry, western blot, etc.) and should be chosen based on the platform that can successfully show accurate potency of a particular drug candidate. Here we show the utility of the In-Cell ELISA assay platform to assess relative potency of multiple drug therapies using the Cytation10 and Cytation3 cell imaging readers. The Cytation reader is a useful tool for relative potency measurements because it allows for fully automated microscopy (brightfield, fluorescent and confocal) in a multi-well plate reader format that standard plate readers cannot provide. In combination with Gen5 software versions such as Image+ and Image Prime, the user can efficiently analyze data like a standard plate reader with the added imaging benefit that is necessary for an In-Cell ELISA. Both readers can produce image-based potency readouts but vary in their analytical functionality and data analysis settings based on software versions within Gen5. Image and data treatment are important components in the implementation of these methods and the advantages, utility, and considerations of these are discussed here using two case studies. One involves protein expression as a function of cell number while the second uses the reversal of protein aggregate formation as functional end points.