View the slide viewer

Have questions about this assay kit?

Human TrkA Reporter Assay Kit

1 x-96 well format assays
1 x-384 well format assays
1 x-96 well format assays
1 x-384 well format assays

Product Description and Product Data

This is an all-inclusive cell-based luciferase reporter assay kit targeting the Human Tropomyosin receptor kinases A (TrkA) which is also commonly referred to as Neurotrophic Tyrosine Kinase Receptor, type 1 (NTRK1). INDIGO’s TrkA reporter assay utilizes proprietary mammalian cells that have been engineered to provide constitutive expression of TrkA. In addition to TrkA Reporter Cells, this kit provides two optimized media for use during cell culture and in diluting the user’s test samples, a reference activator, Luciferase Detection Reagent, and a cell culture-ready assay plate. The principal application of this assay is in the screening of test samples to quantify any functional activity, either activating or inhibitory, that they may exert against human TrkA, or the coupled Ca+2∙calcineurin / NFAT signal transduction pathway. This kit provides researchers with clear, reproducible results, exceptional cell viability post-thaw, and consistent results lot to lot. Kits must be stored at -80C. Do not store in liquid nitrogen. Note: reporter cells cannot be refrozen or maintained in extended culture.


  • Clear, Reproducible Results

  • All-Inclusive Assay Systems
  • Exceptional Cell Viability Post-Thaw
  • Consistent Results Lot to Lot

Product Specifications

Target TypeGrowth Factor Receptor
Receptor FormNative
Assay ModeAgonist, Antagonist
Kit Components
  • TrkA Reporter Cells
  • Cell Recovery Medium (CRM)
  • Compound Screening Medium (CSM)
  • NGF-b, (ref. agonist; in PBS/0.1% BSA )
  • Detection Substrate
  • Detection Buffer
  • White, sterile, cell-culture ready assay plate
Shelf Life6 months
Orthologs AvailableNo
Shipping RequirementsDry Ice
Storage temperature-80C


Activation dose-response assays were performed according to the protocol provided in this Technical Manual. 200 µl / well of TrkA Reporter Cell suspension was dispensed into the 96-well assay plate, which was then incubated for 4 hours. The concentrated stock of NGF-β (provided), NT-3, NT-4 and BDNF (all from Peprotech) were further diluted using CSM to produce treatment media at the desired assay concentrations. The pre-culture media were discarded from the assay wells and 200 µl / well of the prepared treatment media were dispensed (n = 3/conc.), including ‘untreated’ control wells. Following a 22-hour incubation period treatment media were discarded, Luciferase Detection Reagent was added, and luminescence intensity per well was quantified. Values of average relative light units (RLU) and corresponding values of standard deviation (SD), percent coefficient of variation (%CV), Fold-Activation and Z’ were determined for each treatment concentration. Non-linear regression analyses of Fold Activation vs. Log10[ng/mL] and EC50 determinations were performed using GraphPad Prism software.

Target Background

Tropomyosin receptor kinases A, B and C constitute a family of receptors denoted as TrkA, TrkB, and TrkC. Trk’s are single-pass transmembrane receptors that contain an extracellular ligand-binding domain, transmembrane domain, and an intracellular tyrosine kinase domain. Neurotrophins, the physiological activators of Trk receptors, comprise a group of proteins that include Nerve Growth Factor beta (NGF-β), Neurotrophin 3 (NT-3), Neurotrophin 4 (NT-4) and Brain Derived-Neurotrophic Factor (BDNF). The active forms of these neurotrophins are disulfide-linked homodimer polypeptides. The binding of neurotrophins to Trk’s triggers receptor homodimerization and autophosphorylation. The intrinsic tyrosine kinase activities of activated, dimeric Trk receptor initiate intracellular signaling cascades that include RAS-MAPK, PI3-AKT, and PLCγ pathways. Trk’s are expressed in multiple tissue types, and are primarily involved in neuronal development, neuronal proliferation, and avoidance of programmed cell death. Chromosomal rearrangements of NTRK1-3 may result in gene fusions have been clinically validated as oncogenic drivers in a wide array of human cancers. Not surprising, the Trk receptors command much interest as targets for drug development and drug safety screening. Topical recombinant human nerve growth factor beta (rhNGF-β) has been FDA-approved for the treatment for patients with neurotropic keratitis, as well as Trk inhibitors for the treatment of patients with solid tumors harboring NTRK gene fusions. It is also widely accepted that neurotrophins contribute to the pain suffered in osteoarthritis, and anti-NGF antibodies are efficacious in reducing these pain symptoms.

INDIGO’s TrkA Reporter Cells include the luciferase reporter gene functionally linked to tandem consensus sequences of NFAT genetic response elements upstream of a minimal promoter. Activated NFAT binds to these response elements to seed the formation of a complete transcription complex that drives Luc gene expression. Thus, quantifying changes in luciferase expression in the treated reporter cells provides a sensitive surrogate measure of the changes in human TrkA activity.

Therefore, the principal application of this reporter assay is in the screening of test compounds to quantify any functional activity that they may exert against TrkA, or the coupled Ca+2∙calcineurin / NFAT signal transduction pathway.

Also available as a service

Tropomysin Receptor Kinase A (TrkA; NTRK1)

Have questions about this assay kit?