The latest technologies, such as AlphaLISA ™, HTRF® , and DELFIA® have emerged precisely to address these limitations. All of them eliminate washing and separation steps, simplifying the workflow without sacrificing analytical quality.
From heterogeneous to homogeneous immunoassays
Classical ELISA requires multiple incubation and washing stages, which increases inter-well variability and limits miniaturization.
In contrast, homogeneous technologies such as AlphaLISA ™ and HTRF® They allow the entire test to be performed in a single mixture and in the same well, reducing experimental time and handling errors.
Furthermore, by eliminating the washing stages, these techniques become more reproducible. Automatable and scalable, essential characteristics in laboratories that work with large volumes of samples or drug screening projects (HTS).
AlphaLISA ™ : Sensitivity and versatility without washing
AlphaLISA ™ technology It is based on emitting and receiving microspheres that generate a luminescent signal when they are in proximity (after the analyte-antibody binding).
Its physical principle allows the detection of protein-protein, receptor-ligand, or antigen-antibody interactions with sensitivity in the picomolar or even femtomolar range.
It is especially useful for:
- Detection of human or murine immunoglobulins (IgG, IgM, IgE, Fc fragments).
- Cytokine and receptor binding assays (TNF/TNFR, IL6/IL6R, IL23/IL23R, etc.).
- Immune checkpoint studies (PD-1/PD-L1, CTLA4/CD80, CD47/SIRPα).
Thanks to its homogeneous format, AlphaLISA is ideal for laboratories seeking high read rates and minimal handling , without compromising sensitivity.
HTRF® : Time-resolved fluorescence for maximum accuracy
HTRF® (Homogeneous Time-Resolved Fluorescence) combines the FRET (resonance energy transfer) technique with delayed fluorescence of lanthanides such as europium or terbium.
This delay allows us to avoid autofluorescence and background noise, offering more accurate results even in complex biological matrices.
Among its main applications are:
- Intracellular signaling assays (GPCR, protein phosphorylation).
- Protein-receptor or protein-protein interactions.
- Antibody affinity and kinetics studies.
HTRF is a natural alternative to ELISA in cases where rapid quantification is required, without washing and with a greater dynamic range.
DELFIA® : the bridge between ELISA and homogeneous techniques
DELFIA® technology maintains a format similar to that of the traditional ELISA, but introduces time-resolved fluorescent detection instead of a colorimetric readout.
This improvement significantly expands the dynamic range and signal stability, resulting in greater accuracy in quantization.
In addition, DELFIA ™ EuTDA Cytotoxicity reagents allow for the measurement of cell cytotoxicity (ADCC) without resorting to radioisotopes, safely and sensitively replacing older chromium-51 release assays.
Current applications in research
These technologies cover all stages of biotherapeutic development:
- Screening of candidates using receptor-ligand binding assays.
- Functional characterization of therapeutic antibodies (ADCC, CDC, affinity for FcγR and FcRn).
- Bioprocess control (detection of host proteins, residual DNA, serum albumin).
Its compatibility with multimode equipment such as VICTOR ™ Nivo™, EnSight™ or EnVision™ Nexus™ from Revvity, allows all these assays to be integrated into a single reading platform.
Towards a new generation of immunoassays
Adopting homogeneous technologies such as AlphaLISA ™ and HTRF® not only simplify daily work: they represent a paradigm shift in the way immunoassays are approached.
At Proquinorte , we support laboratories taking this step, offering technical advice and access to state-of-the-art kits and equipment for biological research.
