A Homogenous Transcreener® UDP² TR-FRET Glycosyltransferase Assay for High Throughput Screening

About the Transcreener UDP2 Glycosyltransferase Assay Kits

The Transcreener UDP2 Glycosyltransferase Assay is a single step, homogenous, fluorescent assay for the detection and screening of UDP-producing enzymes. Direct detection of UDP with a fluorescence polarization (FP) or TR-FRET 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. Based on BellBrook Lab’s proprietary nucleotide immunodetection technology, the Transcreener UDPGlycosyltransferase Assay is compatible with any enzyme class that produces UDP, including UDP-glucose-, UDP-galactose- and UDP-glucuronosyl-transferases as well as glycogen, hyaluronan and cellulose synthases.

Learn how researchers at the Genesis Biotechnology group used the Transcreener UDP assay in a high throughput screen to discover  Clostridium difficile (C. difficile) toxin B (TcdB) inhibitors.

Direct Detection of UDP for Glycosyltransferases

Transcreener UDP Glycosyltransferase Assay FP Readout

The workhorse. Used in many large screens. Best deck and signal stability.

Transcreener UDP Glycosyltransferase Assay FI Readout

Positive FI signal. Compatible with simple fluorescence plate readers. Faster read time than FP or TR-FRET.

Transcreener UDP Glycosyltransferase Assay TR-FRET Readout

For customers who prefer TR-FRET detection. Uses the same filter set as HTRF®.

Target Class Examples

  • Glucosyltransferase
  • Galactosyltransferase
  • N-acetylglucosyltransferase
  • N-acetylglucosaminyltransferase
  • Xylotransferases
  • Glucoslceramide synthase


  • Screen compound libraries for inhibitors
  • Hit confirmation
  • IC50 Determination
  • Determine inhibitor selectivity between enzymes
  • Measure glycosyltransferase activity

Simple, “Mix-and-Read” Assay Format

Use with Diverse Donor and Acceptor Substrates

Glycosyltransferase Assay Examples with Different Enzymes

GALNT2, GALNT3, BGalT1, and Toxin B substrates were titrated in 4 buffers. Raw data converted to product formation show a linear correlation of the enzyme with the UDP product, confirming initial velocity conditions.

UDP Donors

  • UDP-glucose
  • UDP-galactose
  • UDP-GlcNAc
  • UDP-GalNAc
  • UDP-xylose
  • UDP-glucuronic acid

Robust, HTS-Compatible Assay

Outstanding Deck and Signal Stability

Deck stability demonstrates the ability of the reagents to remain functional after pre-mixing and awaiting dispensing. Plate stability shows the consistency of reagent signal to be read post assay completion. The stability of the reagents provides high quality data and simplifies automation for high throughput screens.

More Sensitive

Excellent signal and Z’ using less than 1 μM UDP-sugar.

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