释义：

AlphaScreen relies on the use of Donor and Acceptor beads that are coated with a layer of hydrogel providing functional groups for bioconjugation. When a biological interaction between molecules brings the beads into proximity, a cascade of chemical reactions is initiated to produce a greatly amplified signal. Upon laser excitation, a photosensitizer in the Donor bead converts ambient oxygen to a more excited singlet state. The singlet state oxygen molecules diffuse across to react with a chemiluminescer in the Acceptor bead that further activates fluorophores contained within the same bead. The fluorophores subsequently emit light at 520-620 nm. In the absence of a specific biological interaction, the singlet state oxygen molecules produced by the Donor bead go undetected without the close proximity of the Acceptor bead. AlphaScreen has successfully been developed for enzyme assays (kinase, helicase, protease, ...), interaction assays (ligand/receptor, protein/protein, protein/DNA), immunoassays, and GPCR functional assays (cAMP, IP3).

AlphaScreen 依赖于使用 Donor 和 Acceptor 微珠，这些微珠涂有一层水凝胶，提供生物偶联的功能基团。当分子之间发生生物相互作用并使微珠接近时，化学反应级联被启动，从而产生大幅度放大的信号。在激光激发下，Donor 微珠中的光敏剂将环境氧气转化为更激发的单重态。单重态的氧分子扩散到 Acceptor 微珠，反应后激活同一微珠内的荧光分子。荧光分子随后在 520-620 nm 处发射光。在没有特定生物相互作用的情况下，Donor 微珠产生的单重态氧分子无法检测到，除非 Acceptor 微珠足够接近。AlphaScreen 已成功开发用于酶测定 (激酶、解旋酶、蛋白酶等) 、相互作用测定 (配体/受体、蛋白质/蛋白质、蛋白质/DNA) 、免疫测定和 GPCR 功能测定 (cAMP、IP3)。