hCB2R High Content Screening (HCS) Service
Determine CB2 ligand binding to the receptor in living cells with our proprietary fluorescent probe CELT-331.
A service based on imaging and fluorescence intensity measurement that rapidly classifies and characterises your candidates without radioisotopes, enabling the discovery and selection of promising compounds.
For full technical details, assay parameters and validation datasheets, see the CB2 HCS brochure.
What is this service?
Celtarys’ CB2 High Content Screening (HCS) is a live‐cell (HEK-293T hCB2R), image‐based binding assay that uses CELT-331, our proprietary hCB2R fluorescent ligand, imaged on Operetta CLS (Ex 646 nm / Em 662 nm). The assay allows quantification of IC50 and Ki via Cheng-Prusoff, using CELT-331 at 80 nM to maximise sensitivity while maintaining a robust specific signal (non-specificity defined with 10 μM GW405833). Our internal validation shows saturable, displaceable binding of CELT-331 and good agreement of Ki values with orthogonal formats for several reference agonist/antagonist molecules (e.g., GW405833, MDMB-CHMICA, adamantyl-quinolinone, AMB FUBICA, AB- FUBICA, Rimonabant, MJ15). See the brochure for data tables and images.
Furthermore, unlike classical radioligand assays, HCS allows molecular interactions to be studied in the context of a living cell, evaluating not only binding (data consistent with orthogonal methods), but also subcellular localisation, toxicity and associated morphological effects. For further information, please download the following technical document.
Why choose Celtarys?
| What we offer (Celtarys CB2 HCS) | Typical market alternatives | So what? (Benefit to you) |
|---|---|---|
Live‑cell HCS imaging in HEK‑293T–hCB2R with fluorescent ligand CELT-331; confocal capture on Operetta CLS. | Membrane‑based radioligand binding or homogeneous binding. | Physiologically relevant context + visual; not just a bulk signal. |
Whole-cell readout in intact cells preserves the physiological context and native conformation of the target. | Membrane lysates may contain a mix of membranes (ER, Golgi, mitochondria, etc.) with many associated proteins that can bind unspecifically to the tracer. | Cleaner specificity and affinity values closer to the real physiological interaction, with fewer artefacts. |
Non‑radioactive fluorescent tracer workflow (no isotopes) | Radioligand panels still common for CB2 profiling. | Safer, simpler logistics and compliance; no isotope waste or licensing. |
Numeric readouts and visual deliverables: representative images, segmentation metrics & displacement curves. | Numeric readouts only with limited visual diagnostics. | Higher confidence and faster troubleshooting; fewer repeat cycles. |
Transparent affinity: we provide IC50 [tracer] = 80 nM, Kd ≈ 160 nM, and compute Ki via Cheng– Prusoff (formula shown) | Reporting varies; Ki sometimes provided without [L] and Kd context. | Trustworthy crossplatform comparisons; anyone can recalcula |
Faster delivery: ~7–10 business days from compliant receipt*. | Often ~14–21 business days (or longer) depending on queue/panel. | Decide sooner; propose follow-up experiments sooner, lock internal reviews/milestones, and keep chemistry/biology moving with no idle time. |
Sample tracking & stewardship: we acknowledge on receipt and notify before storage expiry (3-month policy) so you can reuse, extend, return, or approve disposal. | Basic intake only; disposal timing not always communicated. | No surprises: plan additional assays or retrieval in time; assured chain-of-custody. |
Single-site execution (all assay steps performed at Celtarys Research). | Distributed, multi-site operations across different labs/regions. | Greater consistency (instrumentation, QC) and lower variability; simpler logistics and a single point of accountability. |
Competitive pricing | High price | Lower total cost per decision |
* Note: The reported delivery time is not inherent to the assay itself but rather determined by internal company processes related to data validation and reporting.
Screening options
We offer a two-step screening strategy so you can quickly rank and thoroughly characterise only the best candidates:
Affinity binding screen (single point): qualitative detection of ligand binding based on fluorescence signal. 1 point readout at 1 µM (percent inhibition vs. tracer control).
Displacement curves to calculate IC50 and estimate Ki values for your compounds. You can choose which concentrations to test.
Compounds showing > 50 % inhibition at 1 µM proceed to a concentration-response displacement curve (choose 5 or 7 concentration points) for IC50 and estimate Ki estimation.Example / Case study (16‑compound cohort)
To illustrate output and decision flow, we completed a CB2 HCS pilot in which sixteen agonist‑candidate molecules were profiled in two steps. First, an affinity binding screen was performed at 1 µM (percent inhibition vs. tracer control). Compounds achieving > 50 % inhibition at 1 µM were advanced to concentration–response displacement analysis (pre‑defined 5‑ or 7‑point series) to derive IC50 and Ki (Cheng–Prusoff). The resulting report delivered rank‑ordering across the cohort, representative images, screen‑stage percent‑inhibition tables, and fitted curves with IC50 / Ki estimates for advanced compounds—providing a clear, decision‑ready view of potency and specificity. To view the report and visualise the data sets from this validation, please refer to the quick study.
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