Discovery of GALNT3 Inhibitors Using a Universal Glycosyltransferase Assay and Orthogonal Pooled Screening

Transcreener UDP2 Assay Kit - FP Readout

The Transcreener® UDP2 Assay with FP readout measures UDP via antibodies selective to UDP and a far-red fluorescent tracer. UDP produced in the reaction competes with the tracer, decreasing fluorescent properties and providing a fluorescent readout. The universal detection method allows screening of virtually any glycosyltransferase in a high throughput format. 

Direct detection of UDP with a fluorescence polarization (FP) readout provides a safe, HTS-compatible alternative to cumbersome radioassay methods and is more sensitive and less subject to interference than coupled assay methods, where the UDP is converted to another product. Used in over millions of wells by pharma since 2006, Transcreener technology is the most extensively validated UDP detection method available backed by the best technical support in the industry. 

This assay is designed to be used with purified enzyme preparations. Transcreener assays are not validated with cell lysates, blood, serum, or other biological samples.

Direct Detection of UDP to Measure Glycosyltransferase Enzymatic Activity

Fluorescence Polarization

UDP Assay Schematic - FP Readout v2


  • Measure enzymatic activity of glycosyltransferases
  • Screen compound libraries for glycosyltransferase modulators
  • Quantify inhibitor potency
  • Inhibitor selectivity profiling
  • Measure drug-target residence time


  • Direct detection of unlabeled UDP
  • Robust Assay Z' > 0.7 under initial velocity conditions
  • Far-red fluorescent readouts minimize compound interference
  • A safe, non-radioactive method
  • Use with UDP concentrations from 1 µM to 1,000 µM
  • Universal - use with virtually any glycosyltransferase

Easy-to-Use, Mix-&-Read, HTS Ready

Run your enzyme reaction, add Transcreener reagents, and read your plates. The UDP assay is compatible with 96, 384, and 1536-well formats. 


Example Applications

The Transcreener UDP Assay is compatible with any enzyme class that produces UDP, including UDP-glucose-, UDP-galactose-, & UDP-glucuronosyl-transferases-, as well as glycogen, hyaluranon, & cellulose synthases. 

Toxin B

Far Red FP Readouts Validated on Major Multimode Readers

SupplierInstrumentFP Assays
TriStar2S LB 942In Review
Tristar 5In Review
Mithras2 LB 943In Review
CytationTM 5Validated
CytationTM 3Validated
CytationTM 1Validated
SynergyTM H1Validated
SynergyTM 2/H4/4Click Me ArrowValidated
SynergyTM HTXNot Capable
SynergyTM Neo 2Validated
POLARstar® OmegaClick Me ArrowValidated
FLUOstar® OmegaNot Capable
PHERAstar® FSXClick Me ArrowValidated
PHERAstar® Plus/FSClick Me ArrowValidated
CLARIOstar® /PlusClick Me ArrowValidated
VANTAstarTMClick Me ArrowValidated
SenseIn Review
Analyst® GT/HTClick Me ArrowValidated
Gemini® XPS/EMNot Capable
SpectraMax® M2/M2eNot Capable
SpectraMax® M5/M5e/FlexStation® 3Not Capable
SpectraMax® ParadigmClick Me ArrowValidated
SpectraMax® iD3/iD5Click Me ArrowValidated
SpectraMax® i3xClick Me ArrowValidated
EnVision®/EnVision® XciteClick Me ArrowValidated
Infinite® M1000/M1000Pro/Safire2TMClick Me ArrowValidated
Infinite® M200Not Capable
Infinite® F500Click Me ArrowValidated
Infinite® F200/UltraevolutionClick Me ArrowContact Us
SparkTM 10MClick Me ArrowValidated

Validation Criteria for Plate Readers

  • 384-Well Format
  • Z'-Factor ≥ 0.7 at 10% conversion of 10 μM ATP
  • Δ mP ≥ 95 mP at 10% conversion of 10 μM ATP
  • Z' and Δ mP specifications to be met using Transcreener ADP2 Assay Reagents
  • Read time to achieve Z' and Δ mP specifications in ≤ 5 minutes

Look for these stickers on instruments that have successfully met the validation criteria. 

The instrument validation program is a collaborative effort with the major suppliers of multimode readers to insure that Transcreener assays perform optimally on your specific instrument. Scientists at BellBrook and/or the instrument vendor have tested Transcreener reagents with each instrument to determine optimal filters and settings for maximal assay performance. We provide you with application notes with all the important details, so you can be confident of success using Transcreener assays on the instrument of your choice. 

Transcreener Instrument Validation

What's Included

What You Will Need