AlphaLISA immunoassays are homogenous bead-based luminescent amplification proximity assays that are highly sensitive and offer a large dynamic range and utilize small sample sizes. AlphaLISA is a proximity assay that involves the production of a luminescent/fluorescent signal after energy is transferred between molecule-bound Acceptor and Donor beads. Donor beads include the photosensitizer, phthalocyanine, which transforms ambient oxygen to a reactive form of O2, singlet oxygen, after illumination at 680nm. The excited singlet oxygen has a half-life of 4usec and within that time can diffuse ~200 nm in solution; if an Acceptor bead is present within that space, energy from the singlet oxygen is transmitted to thioxene derivatives in the Acceptor bead. This energy exchange then results in the light production at 615 nm. If there is no Acceptor bead present, the singlet oxygen falls to its ground state and there is no signal.