Resumen de Plate Reader Compatible 3D-Printed Device for Teaching Equilibrium Dialysis Binding Assays
Cody W. Pinger, Andre Castiaux, Savannah Speed, Dana M. Spence
Plasma protein binding measurements are an important aspect of pharmacology and drug development. Therefore, performing these measurements can provide a valuable and highly practical learning experience for students across many scientific disciplines. Here, we describe the design and characterization of a 3D-printed device capable of performing equilibrium dialysis in order to measure the binding affinity between a fluorescent ligand and a common plasma protein. The device is designed for laboratory automation, having dimensions identical to those of a standard 96-well plate, allowing it to be placed into a plate reader for direct fluorescence quantitation of free ligand. Traditional equilibrium dialysis experiments initially require 5–14 h of user attention; however, a “hands-free” approach is enabled by the technology in this paper, allowing the user to set up the device in a 1 h time period and return the next day for data analysis. Here, we include instructions for measuring and calculating the ligand–receptor binding affinity of fluorescein to albumin with comparisons to values previously reported in the literature. While the described experiment is used for a protein/ligand binding event, the device can also be easily adapted to a simple small molecule diffusion study. As such, the experiment includes aspects of importance for engineering (design), chemistry (diffusion), and biochemistry (binding) students. The design files (.stl files) for the device are included in the Supporting Information so that others may use or modify them.
