Applying label-free dynamic mass redistribution technology to frame signaling of G protein-coupled receptors noninvasively in living cells

Abstract

Label-free dynamic mass redistribution (DMRr) is a cutting-edge assay technology that enables real-time detection of integrated cellular responses in living cells. It relies on detection of refractive index alterations on biosensor-coated microplates that originate from stimulus-induced changes in the total biomass proximal to the sensor surface. Here we describe a detailed protocol to apply DMRr technology to frame functional behavior of G protein-coupled receptors that are traditionally examined with end point assays on the basis of detection of individual second messengers, such as cAaMPp, ca 2+ or inositol phosphates. Tthe method can be readily adapted across diverse cellular backgrounds (adherent or suspension), including primary human cells. Rreal-time recordings can be performed in 384-well microtiter plates and be completed in 2 h, or they can be extended to several hours depending on the biological question to be addressed. entire procedure, including cell harvesting and DMRr detection, takes 1-2 d. © 2011 Nature America, Inc. All rights reserved.