Targeting LRRK2 for Parkinson's Disease with the Transcreener® GDP GTPase Assay

Transcreener GDP Assay Kit - FI Readout

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

The Transcreener Assay offers reagents stability and compatibility with commonly used multimode plate readers. The FI GDP assay kit accommodates GTP concentrations ranging from 0.1 µM to 1,000 µM with excellent data quality (Z' ≥ 0.7) at low substrate conversion ( ≤10%). 

Used in over millions of wells by pharma since 2006, Transcreener is the most extensively validated GDP 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 GDP to Measure GTPase Enzymatic Activity

Fluorescence Intensity (FI)

GDP Assay Kit - FI Readout


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


  • Direct detection of unlabeled GDP
  • Robust Assay Z' > 0.7 under initial velocity conditions
  • Far-red fluorescent readouts minimize compound interference
  • A safe, non-radioactive method
  • Universal - use with virtually any GTPase

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

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


GTPase Profiling Assay - Applications

GTPase FamilyEnzyme
Ras FamilyKRAS
Rho FamilyRhoA
Ran FamilyRan

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 Plate 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 ≤ 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

Transcreener GDP 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