Synthetic ion transporters show promise as therapeutics, but assessing their activity can be time-consuming, limiting the screening of large compound libraries. We developed an automated high-throughput assay that determines 24 EC ₅₀ values in one day. This multi-well fluorescence assay effectively screens Cl⁻/NO₃ ⁻ antiport activity and greatly increases the throughput of vesicle-based anion transport measurements.

Abstract

Ion transport across biological lipid membranes is crucial for both health and disease, prompting investigation into synthetic ion transporters as potential therapeutics. However, state of the art methods for assessing transporter activity are often time-consuming and resource-intensive, hindering the screening of large compound libraries. In this work we have developed an automated high-throughput assay capable of determining 24 EC ₅₀ values in a single day. This assay, adapted from the established lucigenin Cl⁻/NO₃ ⁻ antiport method, has been optimised for multi-well plates with fully automated liquid handling. Notably, our protocol allows for the use of DMSO as a delivery solvent for target molecules, enhancing its versatility. Validation with six standard ion transporters demonstrated a strong correlation between the EC ₅₀ values obtained through our assay and previously reported values, confirming its efficacy and potential for broader applications in the field of ion transport.