Effectively analyze signal transduction pathways of biological relevance. 

Our CellSensor Cell Lines can be used to:

  • Screen for agonists/antagonists within a signaling pathway
  • Identify inhibitors of a specific protein target in a signaling pathway
  • Counterscreen and profile for compound selectivity

View our CellSensor Cell Line Validation Table to find your target and start using the largest collection of fully validated pathway cell lines for your primary and secondary screening today. 

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CellSensor Cell Lines use GeneBLAzer® beta-lactamase reporter technology to provide you with a rapid and sensitive method of analyzing signal transduction pathways exposed to drug candidates or other stimuli.  These cell lines measure compound potency and selectivity and allow for analysis, in a high-throughput manner, of key pathways activated or down-regulated by compounds.

Many intracellular signaling pathways converge at the transcriptional level, where transcription factors bind to DNA enhancer elements that regulate downstream transcription.  We have used lentiviral vectors to produce a series of stable cell lines containing various response elements upstream of the beta-lactamase reporter gene.

When pathways leading to specific enhancer elements are activated in these cell lines, beta-lactamase is produced, which can then be detected in a homogeneous assay with our cell-permeable, ratiometric fluorescent LiveBLAzer-FRET B/G substrate (Figure 1).

Schematic of CellSensor reporter gene assay
Figure 1. Schematic of CellSensor reporter gene assay.  CellSensor cell lines are stably engineered to expression beta-lactamase reporter under the control of pathway-specific response elements. The principle and methods for this assay format are simple.1) Minimal amount of beta-lactamase is expressed in untreated cells or cells treated with a pathway-specific inhibitor. Stimulation of the pathway with a ligand or a constitutively active mutation of a component in the pathway leads to the activation of downstream transcription factor(s) resulting in the beta-lactamase reporter gene expression; 2) Cells are loaded with a cell-permeable beta-lactamase FRET-based substrate.  The detection of the beta-lactamase reporter activity is measured on a bottom-read fluorescence plate reader. Low 460nm (blue)/530nm (green) ratio represents low beta-lactamase activity in untreated or inhibitor treated cells and high 460nm (blue)/530nm (green) ratio represents high beta-lactamase activity in the ligand-stimulated cells or cells expressing a constitutively active pathway.

There are two critical instrumentation features required for CellSensor readout—bottom read capability and compatible filter sets.  Invitrogen has validated several instruments for use with our CellSensor Cell Lines when used with our LiveBLAzer-FRET B/G substrate.

For instrumentation set-up help or a list of validated instruments, please email us at

For Research Use Only. Not for use in diagnostic procedures.