A High Throughput CD39 Assay for the Ectonucleotidase Based on the Transcreener Platform

Discover CD39 Inhibitors with the Transcreener AMP2 Assay

The Transcreener AMP² CD39 Assay directly measures AMP produced by ectonucleoside triphosphate diphosphohydrolase-1 (also known as ENTPD1, NTPDase1, Cluster of Differentiation 39 or CD39). By measuring the production of AMP researchers can effectively determine the activity of the CD39 enzyme. The assay provides a powerful tool to screen entire compound libraries for CD39 modulators to help find new therapeutics for diseases such as cancer.

CD39 is an Important Messenger for Purinergic Signalling

Ectonucleotidases are plasma membrane-bound enzymes with externally oriented active sites that metabolize nucleotides to nucleosides and are crucial for maintaining immune homeostasis. CD39,  hydrolyzes ATP and ADP to AMP.  AMP can further be processed to adenosine leading to a significant impact on many disease states. Recent studies have shown a key role for adenosine in immunosuppression in the tumor microenvironment, and ectonucleotidases are emerging as promising immuno-oncology targets.

Purinergic Signaling

Direct Detection of AMP to Measure CD39 Enzymatic Activity

CD39 Assay Schematic FP
CD39 Assay Schematic TR-FRET


  • Measure Enzymatic Activity of CD39
  • Screen Compound Libraries for CD39 Inhibitors
  • Quantify Inhibitor Potency
  • Inhibitor Selectivity Profiling


  • Direct detection of unlabeled AMP
  • Easy to use, homogenous, one step format
  • Robust Assay Z’ > 0.7 under initial velocity conditions
  • Far-red fluorescent readouts minimize compound interference
  • A safe, non-radioactive method
  • Available in FP or TR-FRET readouts

Easy-to-Use, Mix-and-Read, HTS-Ready Assay

The Transcreener CD39 Assay is in a simple, HTS-ready, mix-and-read format. Run your enzyme reaction, add Transcreener reagents, and read your plates. The assay is compatible with 96, 384, and 1536-well formats.

Detection of AMP Under CD39 Initial Velocity

The assay demonstrates linearity when raw data is converted to AMP using a standard curve. CD39 can use a variety of substrates. Here both ATP and ADP are shown under initial velocity conditions.

Human CD39 Enzyme Titration

Linear Response

cd39 Under Initial Velocity Conditions using ATP and ADP as substrates

Screen for Inhibitors & Perform SAR

Transcreener Assays are designed for screening compound libraries in a high throughput format. Follow up SAR can also be performed using the assay to determine inhibitor potency with ease.

A 1600 compound subset from Chembridge Diversity Library was screened using CD39 and ATP in the Transcreener TR-FRET format resulting in 8 hits shown in green.

1600 Compound Pilot Screen

CD39 Pilot Screen

Acquire Accurate Dose Response Measurements

Robust Assay Yields Quality Data

Z’ measurements using optimized CD39 reaction conditions indicate a robust assay.  Robust data like this is vital for sizeable high throughput screens that are difficult to complete due to massive sample quantity. Both ATP and ADP produce excellent results.

Robust Assay with Excellent Z prime

Far-Red FP & TR-FRET Readouts Validated on Major Multimode Readers

Supplier Instrument FP Assays
TR-FRET Assays
bioteklogo TriStar²S LB 942 in review validated
Mithras² LB 943 in review validated
bioteklogo Cytation™ 5 validated validated
Cytation™ 3 validated validated
Cytation™ 1 validated validated
Synergy™ H1 validated validated
Synergy™ 2/H4/4 validated validated
Synergy™ HTX not capable not capable
Synergy™ Neo 2 validated validated
BMGLABTECH Logo POLARstar® Omega validated validated
FLUOstar® Omega not capable validated
PHERAstar® FSX validated validated
PHERAstar® Plus/FS validated validated
CLARIOstar® /Plus validated validated
VANTAstar validated validated
MDS AT logo Analyst® GT/HT validated validated
Gemini® XPS/EM not capable not capable
SpectraMax® M2/M2e not capable not capable
SpectraMax® M5/M5e/FlexStation® 3 not capable validated
SpectraMax® Paradigm validated contact us
SpectraMax® iD3/iD5 in review validated
perkinElmerLogo EnVision®/EnVision® Xcite validated validated
tecanLogo Infinite® M1000/M1000Pro/Safire2™ validated validated
Infinite® M200 not capable not capable
Infinite® F500 validated validated
Infinite® F200/Ultraevolution contact us contact us
Spark™ 10M validated validated

What's Included

What You Will Need

CD39 Assay Services

Interested in moving your program forward, but don't want to bring an assay in-house? Our scientists can help! BellBrook scientists will use their extensive biochemistry and enzymology expertise to work with you and accelerate your CD39 program.

Assay Development Services

Lead Discovery Services Include:

  • Inhibitor Screening – To identify or confirm activity with the target.
  • Inhibitor Potency Profiling – Dose-response with target and/or related proteins. Fast IC50 results.
  • Residence Time Measurements – Determination of koff using ‘jump dilution’ enzymatic assay method.
  • Mechanism of Action Studies – Kinetic analysis to define the mode of inhibition.

Contact Us to Learn More

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