College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071, China.
Anal Chim Acta. 2013 Nov 1;801:91-6. doi: 10.1016/j.aca.2013.09.050. Epub 2013 Sep 28.
We report a magnetic-particle (MMP)-based chemiluminescence enzyme immunoassay (CLEIA) for free prostate-specific antigen (f-PSA) in human serum. In this method, the f-PSA is sandwiched between the anti-PSA antibody coated MMPs and alkaline phosphatase (ALP)-labeled anti-f-PSA antibody. The signal produced by the emitted photons from the chemiluminescent substrate (4-methoxy-4-(3-phosphatephenyl)-spiro-(1,2-dioxetane-3,2'-adamantane)) is directly proportional to the amount of f-PSA in a sample. The present MMP-based assay can detect f-PSA in the range of 0.1-30 ng mL(-1) with the detection limit of 0.1 ng mL(-1). The linear detection range could match the concentration range within the "diagnostic gray zone" of serum f-PSA levels (4-10 ng mL(-1)). The detection limit was sufficient for measuring clinically relevant f-PSA levels (>4 ng mL(-1)). Furthermore, the method was highly selective; it was unaffected by cross-reaction with human glandular kallikrein-2, a kallikrein-like serine protease that is 80% similar to f-PSA. The proposed method was finally applied to determine f-PSA in 40 samples of human sera. Results obtained using the method showed high correlation with those obtained using a commercially available microplate CLEIA kit (correlation coefficient, 0.9821). This strategy shows great potential application in the fabrication of diagnostic kits for determining f-PSA in serum.
我们报告了一种基于磁性粒子（MMP）的化学发光酶免疫分析（CLEIA），用于检测人血清中的游离前列腺特异性抗原（f-PSA）。在这种方法中，f-PSA 夹在包被有抗 PSA 抗体的 MMP 和碱性磷酸酶（ALP）标记的抗 f-PSA 抗体之间。化学发光底物（4-甲氧基-4-（3-膦酸基苯基）螺环[1,2-二氧乙烷-3,2'-金刚烷]）发出的光子产生的信号与样品中 f-PSA 的量成正比。本基于 MMP 的测定方法可以检测 0.1-30ng/mL 范围内的 f-PSA，检测限为 0.1ng/mL。线性检测范围与血清 f-PSA 水平（4-10ng/mL）的“诊断灰色区域”内的浓度范围相匹配。检测限足以测量临床上相关的 f-PSA 水平（>4ng/mL）。此外，该方法具有高度选择性；它不受人组织激肽释放酶-2（一种与 f-PSA 有 80%相似的激肽样丝氨酸蛋白酶）的交叉反应影响。该方法最终应用于 40 个人血清样本中 f-PSA 的测定。该方法获得的结果与市售微孔板 CLEIA 试剂盒（相关系数为 0.9821）获得的结果高度相关。这种策略在制备用于检测血清中游离 PSA 的诊断试剂盒方面具有很大的潜在应用。
