Our GPCR Functional Assay Services

Tanso Biosciences provides super-sensitive and reliable functional assays for more than 300 human G-protein-coupled receptors (GPCRs) to expand frontiers, accelerate drug discovery, and reduce R&D risks.Our assay services are available on a contract basis and through partnership.

Off-Target Screening

This test characterizes selectivity and specificity of hit compounds and screens out ones with unwanted potencies on any human GPCRs.

Assay services: off-target screening

On-Target Screening

This drug discovery tool screens for compounds with potencies on target receptors.

“Assay services: on-target screening

Key Features

Measures receptor activity

  • Our assay depends on signals downstream of receptors and is thus highly specific. It does not allow many false positives in or false negatives out. In contrast, the binding assay is deemed poorly specific and unreliable for screening GPCRs and other transmembrane proteins.
  • It screens for agonists, inverse agonists, positive allosteric modulators (PAMs), and negative allosteric modulators (NAMs), as well as antagonists.

Provides a one-fits-all solution in a single assay format

  • Our assay detects GPCR activation in a single format, regardless of the subtypes of Gα proteins coupled to the receptor of interest, thereby
    • serving as the most versatile and cost-effective GPCR drug-discovery tool and
    • making it possible to compare the potencies of a compound at multiple GPCRs and profile it in a reliable manner.
  • Our screening panel covers all the human non-sensory GPCRs including orphan receptors.
  • Our assay is equally sensitive and specific whichever Gα protein among Gs, Gi/o, Gq, and G12/13 the receptors of interest are coupled with, making research far more efficient than existing methods.
  • It has been validated with >99% (216 out of 218) of non-orphan GPCRs.
  • Our method has made orphan receptors feasible targets for drug discovery.

Uses native GPCRs

There is no modification in sequences that may compromise the results.

Low in cost, high in throughput

  • Requires no special equipment or expensive reagents
  • Receptors are transiently expressed on microplates; there is no need to maintain hundreds of cell lines.


Our services help maximize opportunities and minimize risk in drug research and development.

  • On-target and off-target screening for drug discovery
  • Profiling of seed/hit/lead compounds
  • Strategy development
  • In-licensing assessment
  • Drug repositioning
  • Preclinical off-target screening

Contact Us

Ask Cosmo Bio Co., Ltd. for further information about our contract services and quotations.