AlphaLISA Assays An Alternative To Conventional ELISAsSource: Tecan
AlphaLISA is a homogeneous, no-wash alternative to conventional ELISAs based on PerkinElmer’s bead-based Alpha (Amplified Luminescent Proximity Homogeneous Assay) technology. AlphaLISA assays can be set up as sandwich or competitive immunoassays to detect and quantify molecules of interest in biological samples.
High energy excitation of photosensitizer molecules within the AlphaLISA donor beads at 680 nm converts ambient oxygen to singlet oxygen, which in turn is able react with the chemistry in the acceptor beads if these are in close proximity. A cascade of energy transfer steps ultimately results in the generation of a strong luminescence signal at 615 nm, indicating specific binding between the molecules attached to the two bead types. The fluorophores embedded in the AlphaLISA acceptor beads produce a narrower bandwidth signal than the acceptor beads used for classical AlphaScreen® assays.
This makes AlphaLISA assays less prone to signal interference at wavelengths of <600 nm, increasing the sensitivity and robustness of the assay. The use of dedicated AlphaLISA optics permits the analysis of target molecules in blood and serum by drastically reducing the effect of hemoglobin within a sample.