Features:

• No-wash steps, no separation steps
• Ease-of-use: few addition steps, fast assay development
• Broad range of affinities: detect strong or weak interactions, from pM to mM affinity
• Distance: measure very large protein or antibody complexes – spanning up to 200 nm or more
• High avidity: multiple binding sites on each bead enables use of nanomolar concentrations of antibodies or proteins, as well as use of low affinity binders

AlphaLISA technology allows detecting the binding of target proteins in a highly sensitive, quantitative, reproducible and user-friendly mode. In this AlphaLISA assay, a biotinylated PDGF-BB binds to the Streptavidin-coated Alpha Donor beads, while His tagged PDGFRα is captured by Anti-His AlphaLISA Acceptor beads. When PDGF-BB binding to PDGFRα happens, Donor beads and Acceptor beads come into close proximity. The excitation of the Donor beads provokes the release of singlet oxygen molecules that triggers a cascade of energy transfer in the Acceptor beads, resulting in a sharp peak of light emission at 615 nm.

Platelet-derived growth factor (PDGF) is one of numerous growth factors that regulate cell growth and division. PDGF is a dimeric glycoprotein that can be composed of two A subunits (PDGF-AA), two B subunits (PDGF-BB), or one of each (PDGF-AB). The dimeric isoforms are differentially expressed in various cell types and their effects are mediated through two cell surface tyrosine kinase receptors, platelet-derived growth factor receptors, termed alpha (PDGFRα) and beta (PDGFRβ). Differences exist in isoform binding to each receptor. PDGF and PDGFR are involved in human cancer development and progression through autocrine stimulation of tumor cell growth. Blocking PDGF and PDGFR binding has been considered as a potential target for antitumor and antiangiogenic therapy.