<p>Methods are provided to detect changes in cells without the use of detection labels In one embodiment, detection of responses of cells to stimuli comprises immobilizing one or more extracellular matrix ligands to a surface of a colopmetric resonant reflectance biosensor or a grating-based waveguide biosensor, and adding the cells having cell surface receptors specific for the one or more extracellular matrix ligands to the biosensor Changes in cells are then detected by the biosensor before and after introduction of stimuli to the biosensor.</p>
