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

Transcreener UDP2 Assay Kit - FI Readout

The Transcreener® UDP2 Assay Kit with FI readout directly measures UDP via antibodies selective to UDP and a fluorescent tracer. Enzymatically generated UDP displaces the tracer from an antibody-quencher conjugate, resulting in increased fluorescence. The universal detection method allows screening of virtually any glycosyltransferase in a high throughput format. 

The Transcreener UDP Assay Kit with FI readout produces a simple fluorescent intensity output which can be read on even the most basic fluorescence readers typically found in academic and therapeutic research labs as well as more complex multimode plate readers. Direct detection of UDP with a fluorescence intensity (FI) 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 Intensity

UDP Assay Schematic - FI Readout


  • 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
  • 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
  • Universal - use virtually with any glycosyltransferase

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

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


Example Applications

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

Toxin B

Excellent Z' With Low Levels of UDP Conversion

Far Red FI Readouts Validated on Major Multimode Readers

SupplierInstrumentFI Assays
TriStar2S LB 942Click Me ArrowValidated
Tristar 5Click Me ArrowValidated
Mithras2 LB 943Click Me ArrowValidated
CytationTM 5Validated
CytationTM 3Validated
CytationTM 1Validated
SynergyTM H1Validated
SynergyTM 2/H4/4Click Me ArrowValidated
SynergyTM HTXValidated
SynergyTM Neo 2Validated
POLARstar® OmegaClick Me ArrowValidated
FLUOstar® OmegaClick Me ArrowValidated
PHERAstar® FSXClick Me ArrowValidated
PHERAstar® Plus/FSClick Me ArrowValidated
CLARIOstar® /PlusClick Me ArrowValidated
VANTAstarTMClick Me ArrowValidated
SenseClick Me ArrowValidated
Analyst® GT/HTClick Me ArrowValidated
Gemini® XPS/EMClick Me ArrowValidated
SpectraMax® M2/M2eClick Me ArrowValidated
SpectraMax® M5/M5e/FlexStation® 3Click Me ArrowValidated
SpectraMax® ParadigmClick Me ArrowContact Us
SpectraMax® iD3/iD5Click Me ArrowValidated
SpectraMax® i3xIn Review
EnVision®/EnVision® XciteClick Me ArrowValidated
Infinite® M1000/M1000Pro/Safire2TMClick Me ArrowValidated
Infinite® M200Click Me ArrowValidated
Infinite® F500Click Me ArrowValidated
Infinite® F200/UltraevolutionClick Me ArrowValidated
SparkTM 10MClick Me ArrowValidated

Validation Criteria for Microplate Readers

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

Look for these validation 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. 

What's Included

What You Will Need

Transcreener UDP2 Assay Kits - FI Readout

*For custom or bulk orders (over 100,000 wells), please contact us (info@bellbrooklabs.com) for a quote.

Assay Plates for FI