MAb Anti GST-Eu cryptate HTRF®

Eu cryptate-labeled anti-GST antibody for capturing GST-tagged proteins in protein/protein interaction assays.
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  • No-wash No-wash
  • Ease-of-use Ease-of-use
  • High affinity High affinity
Eu cryptate-labeled anti-GST antibody for capturing GST-tagged proteins in protein/protein interaction assays.


MAb Anti GST-Eu cryptate is an IgG2a raised against Glutathione S-transferase labeled with Eu. It has been shown to react with GST-tagged fusion proteins from a large number of expressing vectors.

This reagent can be used in both biochemical and cellular formats to study a wide variety of interactions: protein/protein, protein/peptide, protein/DNA, protein/RNA, protein/carbohydrate, protein/small molecule, receptor/ligand.

HTRF can detect a broad range of affinity constants ranging from picomolar to low millimolar.



Assay principle

In an HTRF interaction assay, one partner is labeled (directly or indirectly) with the donor, and the other with the acceptor (again, directly or indirectly). The intensity of the signal is proportional to the binding of the 2 partners. In the example shown here: MAb Anti GST-Eu cryptate binds to the GST tagged partner A while partner B* binds to a specific Ab labeled with an HTRF acceptor. *partner B can also be biotinylated, tagged, Fc fused. In these cases, use the corresponding HTRF reagent (anti-Tag, anti-species, protA, Streptavidin) labeled with acceptor for the detection.
assay principle of detection assay using HTRF MAb Anti GST-Eu cryptate

Assay protocol

The example on the right describes the protocol using a 20 µL final assay volume for detecting an interaction between a GST-tagged partner A and a non-tagged partner B*. Dispense the 2 partners (10 µL), incubate, add MAb Anti GST-Eu cryptate (5 µL) and anti-partner B labeled with acceptor (5 µL), incubate and read. *partner B can also be biotinylated, tagged, Fc fused or directly labeled. In these cases, use the corresponding HTRF reagent (anti-Tag, anti species, protA, Streptavidin) labeled with acceptor for the detection.
assay protocol of detection assay using HTRF MAb Anti GST-Eu cryptate

How do the number of tests relate to active moiety?

The average conjugate quantity per well reflects overall biological material content. Using the active moiety amount is generally preferred to the quantity of total conjugate. For Cryptate and d2 conjugates, the total conjugate amount equals that of the active moiety, since the molecular weight of the label is negligible. This is not the case for XL665 labeled entities for which the quantity of total conjugate will vary depending on the final molar ratio of the XL665 conjugate, however, the amount of active moiety, provided by Cisbio, is constant and based on the number of tests ordered.
description of the active moiety in an HTRF conjugate

Recommended quantities of Cryptate and XL665 conjugates

Cryptate conjugates must not be excessive in order to prevent reader saturation and an unacceptable level of background. In most cases, a cryptate concentration of 1 to 5nM is appropriate, and will generate 20,000 to 80,000 cps at 620 nm depending on the HTRF compatible reader used. The XL665 conjugate must match its assay counterpart as closely as possible in order for the maximum number of biomolecules to be tagged with the XL665 acceptor. Thus, to detect a tagged molecule at an assay concentration of 20nM, the concentration of anti-Tag-XL665 should be equimolar or higher.

p53/HDM2 binding assay

p53, a tumor suppressor protein activated in response to DNA damage, is regulated by the binding of HDM2 which induces ubiquitin-medicated degradation of p53. Our HTRF assay was developed to monitor p53/HDM2 binding, to assess the effect of serine phosphorylation within the p53 N-terminus on HDM2 binding, and to determine the relative affinity of a p53 homologue, p73, for HDM2. This assay employs a site-specific biotinylated p53 protein, a GST-fused HDM2 protein, streptavidin-XL665 and europium cryptate-labeled anti-GST antibody. Kane et al. - Development of a binding assay for p53/HDM2 by using homogeneous time-resolved fluorescence. Anal Biochem. 2000;278: 29-38.
p53/HDM2 binding assay using HTRF MAb Anti GST-Eu cryptate and streptavidin XL665 for detection

Applications of HTRF and Tag-lite-lite Assays for HTP Antibody Screening

In collaboration with Bristol Myers Squibb - Scientific Presentations

Academia/Industry Cross-Fertilization through Translational Research

In collaboration with Scripps - Scientific Presentations

HTRF-powered detection of ubiquitin-like protein (UBL) signaling and interactions

In collaboration with Sanford/Burnham - Scientific Presentations

The use of HTRF in biologics discovery

In collaboration with MedImmune - Scientific Presentations

HTRF: One technology, many uses in a pre-clinical laboratory setting

Benefits and considerations of HTRF - Scientific Presentations

Exploiting HTRF for novel drug classes: Stabilizing 14-3-3 protein-protein interactions

In collaboration with Lead Discovery Center GmbH - Scientific Presentations

HTRF a versatil approach for 7TM drug discovery

In collaboration with MRC - Scientific Presentations

HTRF protein-protein interaction reagents

Benefit from unlimited flexibility for your assay development - Flyers

Addressing the interactome with protein-protein assays

Cover all PPIs with one approach - Brochures

HTRF -A Beneficial Tool for Lead Optimization of Biotherapeutics

In collaboration with Boehringer Ingelheim - Posters

Product Insert Anti GST-Eu / 61GSTKLA-61GSTKLB

61GSTKLA-61GSTKLB - Product Insert

HTRF PPI your dream assay served on a plate

Sandwiches aren't just for eating - Infographics

Best practices for pharmacological characterization of PPI inhibitors

Easy pharmacological characterization of PPI modulators. - Technical Notes

HTRF assays handle low- to high affinity protein-protein interactions

Deciphering low- and high affinity interactions - Application Notes

Nuclear receptor ligand identification with HTRF

Monitoring nuclear receptor binding with HTRF assays - Application Notes

HTRF addresses large protein-protein interaction complexes

Challenge large complexes with HTRF assays - Application Notes

A brief history of Protein-Protein Interactions

How well do you know PPI? - Infographics

HTRF Product Catalog

All your HTRF assays in one document! - Catalog

A guide to Homogeneous Time Resolved Fluorescence

General principles of HTRF - Guides

How HTRF compares to Western Blot and ELISA

Get the brochure about technology comparison. - Brochures

Virology research solutions using HTRF Protein-Protein Interaction assays

See how peer researchers challenge the viral life cycle with PPI assays - Application Notes

Homogeneous PPi assays for virology research

A review compiling published scientific data about virology research - Application Notes

Solutions for CAR-T research

Advance your CAR-T cell research - Flyers

Improve PROTAC Targeting Kinase Discovery

Application note describing how HTRF binding kits can help assessing PROTAC targeting kinase - Application Notes

Safety Data Sheet Anti GST-Eu / 61GSTKLA

61GSTKLA - Safety Data Sheet

Batch Information Anti GST-Eu / 20230129

61GSTKLA Batch 101B - Batch Information

Batch Information Anti GST-Eu / 20240303

61GSTKLA Batch 104A - Batch Information

Batch Information Anti GST-Eu / 20250728

61GSTKLA Batch 106A - Batch Information

Safety Data Sheet Anti GST-Eu / 61GSTKLB

61GSTKLB - Safety Data Sheet

Batch Information Anti GST-Eu / 20240303

61GSTKLB Batch 104A - Batch Information

Batch Information Anti GST-Eu / 20240510

61GSTKLB Batch 101A - Batch Information

Batch Information Anti GST-Eu / 20250728

61GSTKLB Batch 106A - Batch Information

Plate Reader Requirement

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