Description
Monoclonal anti-VHH antibody has been labeled with XL665 and binds to the native form of both alpaca and llama VHH, as well as recombinant nanobodies. The binding is rapid and stable, making it an ideal choice for use in a variety of assays including nanobody selection and titration.
HTRF assays offer many advantages over other technologies:
Homogeneous add-and-read format
No wash steps
Low background
Straightforward miniaturization from 96- or 384-well microplates to high density assay formats such as 384-well low volume and 1536-well plates
Stable signal, providing flexibility in time of readout or size of assays
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 resulting signal is proportional to the binding of the 2 partners. In the example shown here, anti-VHH-XL665 binds to the nanobodies raised against protein A, while partner A* binds to a specific Ab labeled with an HTRF donor.
*partner A can also be biotinylated, tagged, or Fc fused. In these cases, use the corresponding HTRF reagent (anti-Tag, anti-species, protA, Streptavidin) labeled with a donor for the detection.
Assay protocol
The example on the right describes the protocol using a 20 µL final assay volume for the detection of an interaction between a nanobody raised against protein A and a non-tagged partner A*. Dispense the two partners (10 µL): i.e. protein A+nanobody, add anti-partner A labeled with donor (5 µL), and anti-VHH-XL665 (5 µL) Then incubate, and finally read.
*partner A can also be biotinylated, tagged or Fc fused. In these cases, use the corresponding HTRF reagent (anti-Tag, anti-species, protA, Streptavidin), labeled with a donor for the detection.
