Our scientists have in-depth experience of label-free technology applied to cell-based assays gained over the past 6 years using Corning Epic, PerkinElmer EnSpire and SRU Bioscience Bind instruments.
These systems incorporate an optical biosensor into a micro-titre plate to measure the cellular response to a stimulus. Specifically, the systems are able to detect changes in mass at the sensor surface resultant from alterations in cell shape and/or protein recruitment or migration to/from the membrane.
The technology is generic being independent of signaling pathway, it is non-invasive (no molecular biology required) and generates a kinetic response over seconds, minutes or hours resulting in an information rich readout.
Label-free techniques are highly suitable for measuring responses in native or physiologically relevant systems such as primary human and animal cells without the need for over-expression or amplification through genetic modifications. This is of great benefit in understanding the molecular pharmacology of a receptor in its native environment, whereas a recombinant system does not necessarily have the natural coupling or utilise the correct signaling pathway.
Label-free techniques may also be of benefit where there is no simple/standard biological readout e.g. for de-orphanisation of receptors and identification of pharmacological “tool” compounds.
Our team has developed assays for a number of 7 Transmembrane Receptors (7TMR) (or GPCR) targets, conducting high throughput screens and mechanistic studies.
We have utilised the Corning Epic system to screen a number of 7-TMR targets including agonist screens for two dual coupled receptors (Gi/Gq and a Gs/Gi couples).
Published proof of concept: Comparing the output from label-free and calcium flux readouts for a muscarininc receptor antagonist screen in a peer reviewed journal. (Ref: Journal of Receptors and Signal Transduction, 2009; 29(3–4): 163–172)
We have developed and validated assays for targets in common cell backgrounds and primary human and animal cells where available. Label-free assays have been used as an orthogonal screening approach to more standard screening assays.
Our experience extends to developing assays with human neutrophils to measure responses to a range of stimuli e.g. chemokines (ref ELRIG 2007 presentation).