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

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), TR-FRET, or all new 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. Based on BellBrook Lab’s proprietary nucleotide immunodetection technology, the Transcreener UDP2 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 Method

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

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

Transcreener UDP² Glycosyltransferase Assay Kits

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

Assay Plates for FI & FP

Assay Plates for TR-FRET

Glycosyltransferase 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 glycosyltransferase 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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Glycosyltransferases As Drug Targets

Glycosyltransferases (GTs) are catalysts for the transfer of a nucleotide sugar donor to a glycosyl acceptor substrate. More than 200 human glycosyltransferases are known to exist and have diverse metabolic and regulatory roles.

Once glycosyltransferase reactions occur, the nucleotide is often a remaining byproduct. In many cases, glycosyltransferases use UDP sugars as donor substrates. Thus, UDP is a product of the reaction. One method to determine glycosyltransferase enzyme activity is to directly measure the UDP formed by the GT. This provides a universal assay technology to assess the activity of any UDP-producing enzyme in real-time.

Transcreener technology uses a simple but highly effective method that consists of an antibody selective to UDP over a UDP sugar donor and a far-red fluorescent tracer. UDP produced in the reaction competes with the tracer changing the fluorescent properties and providing a readout. The assay is a simple mix-and-read format. Perform your enzyme reaction, add the detection reagent, and measure. The simplicity of the system yields robust results but also makes it extremely amiable to HTS.

Glycosyltransferase inhibitors are often targeted for metabolic disorders. Continuing to build an understanding of GT enzymes is step one. Finding therapeutic methods to reign in overactivity requires selective technologies that can help assess the ability to interact with the target. Robust, HTS-ready assays that are accurate yet flexible provide a powerful tool to accelerate discovery.