Skip to main content

HTRF Ubiquitin-Eu cryptate, 5,000 Assay Points

Ubiquitin labeled with Europium Cryptate to monitor protein ubiquitination

For research use only. Not for use in diagnostic procedures.

Product Variants
Part number: 61UBIKLA
Unit Size: 5,000 Assay Points
List price: USD 609.47
Your price:
USD 609.47
USD 609.47 /each
Part number: 61UBIKLB
Unit Size: 20,000 Assay Points
List price: USD 1,911.00
Your price:
USD 0.00
USD 1,911.00 /each


Ubiquitination plays a key role in regulating protein degradation, and is carried out by the conjugation of ubiquitin to target proteins through the sequential activity of three enzymes: E1, E2 and E3. Poly-ubiquitinated proteins are then subject to degradation by proteasomes.

The ubiquitin pathway is associated with many pathologies such as cancer, muscle atrophy, inflammation, viral infection, and metabolic and neurodegenerative disorders. The Ubiquitin-Eu cryptate allows flexible assay development assessing each step in the ubiquitin pathway.


Assay Points
Assay Target Type
Fluorescent reagent
Assay Technology
Shipping Conditions
Shipped Ambient
Unit Size
5,000 Assay Points

Video gallery

How it works

Assay principle

HTRF Ubiquitin assays use ubiquitin labeled with Europium cryptate. Upon the addition of XL665 conjugate, the HTRF signal is proportional to the level of ubiquitination, and remains stable for more than 24 hours. An example of a p53-polyubiquitination assay is shown here.

PPI how it works assay principle htrf ubiquitin cryptate
Assay protocol

HTRF ubiquitin assays have two basic phases: the enzymatic step, followed by the HTRF detection step. 1. Enzymatic step: The target protein is incubated with the ubiquitin enzymes (E2 & E3) and Eu3+-labeled ubiquitin. The reaction starts with the addition of E1 enzyme. 2. Detection step: The ubiquitinated target protein is then detected by the addition of an XL665-labeled reagent that contains EDTA to stop the enzymatic reaction.

PPI how it works assay protocol htrf ubiquitin cryptate


Assay validation

p53 poly-ubiquitination assay

The figure on the right summarizes the results of a p53 poly-ubiquitination assay*

Eu3+-labeled ubiquitin was directly incorporated into the poly-ubiquitin chain on the biotinylated-p53 target protein:

200 nM Biotinylated-p53 was incubated with 300nM E2, 150nM E3, 200nM ATP, and a mixture of Ub-K/Ub (20/500 nM).

8 nM E1 was then added to start the reaction,

The ubiquitin reaction was stopped at various times by adding EDTA.

Poly-ubiquitinated p53 was measured by the addition of streptavidin-XL665.

The enzymatic reaction was linear for up to 50 minutes. The assay had CVs <5% and a S/B of 10 that was stable for several days.

*The ubiquitin assay was performed following the procedure as described by Yabuki et al. in Comb Chem High Throughput Screening. 1999 Oct;2(5):279-87

Assay validation ubiquitin eu cryptate 1



1-1 of 1 Resources
Guide Icon
HTRF solutions, guide to major applications

This guide provides you an overview of HTRF applications in several therapeutic areas.

SDS, COAs, Manuals and more Illuminator

SDS, COAs, Manuals and more

Are you looking for technical documents for this product. We have housed them in a dedicated section., click on the links below to explore.

Scroll Icon