HTRF® Anti-tag reagents toolbox

How do the number of tests relate to active moiety?

The average conjugate quantity per well is information that reflects overall biological material content. For Eu3+ cryptate and biotin conjugates, the total conjugate amount equals that of the active moiety, since the molecular weight of the label is negligible.

For XL665 labeled entities, however, the amount of active moiety will not equal the amount of total conjugate. In practice, using the active moiety amount is generally preferred to the quantity of total conjugate as a basis for calculating reagent usage per well during assay development. The quantity of total conjugate supplied by Cisbio Bioassays will vary depending on the final molar ratio of the XL665 conjugate. The amount of active moiety, however, is constant and based on the number of tests ordered.

HTRF anti-GST for protein: protein interaction

 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.