Li T M, Benovic J L, Buckler R T, Burd J F
Clin Chem. 1981 Jan;27(1):22-6.
A substrate-labeled fluorescent immunoassay for theophylline in serum is described. 8-(3-Aminopropyl)-theophylline is covalently attached to a fluorogenic enzyme substrate, 7-beta-galactosylcoumarin-3-carboxylic acid. Hydrolysis of this theophylline-labeled substrate by beta-galactosidase yields a fluorescent product. When antibody to theophylline interacts with this substrate, the resulting complex is inactive as an enzyme substrate. For measuring theophylline, competitive protein-binding reactions are set up, with the theophylline in the sample competing with the substrate for the antibody-binding sites. The substrate not bound to antibody is hydrolyzed by beta-galactosidase, producing fluorescence that is proportional to the theophylline concentration. Results for theophylline determined by this method in clinical samples of serum correlated well (r > 0.96) with results obtained by gas-chromatographic or enzyme immunoassay procedures. The within-run CV for three control samples ranged from 1.1 to 2.8%, the between-run CB from 2.3 to 4.5%.
本文描述了一种用于血清中茶碱的底物标记荧光免疫测定法。8-(3-氨丙基)-茶碱与一种荧光酶底物7-β-半乳糖基香豆素-3-羧酸共价连接。β-半乳糖苷酶对这种茶碱标记的底物进行水解会产生一种荧光产物。当茶碱抗体与该底物相互作用时，形成的复合物作为酶底物无活性。为了测定茶碱，建立竞争性蛋白质结合反应，样品中的茶碱与底物竞争抗体结合位点。未与抗体结合的底物被β-半乳糖苷酶水解，产生与茶碱浓度成正比的荧光。用该方法测定临床血清样品中茶碱的结果与气相色谱法或酶免疫测定法得到的结果相关性良好（r>0.96）。三个对照样品的批内变异系数在1.1%至2.8%之间，批间变异系数在2.3%至4.5%之间。
