Zhu Xiangdong, Landry James P, Sun Yung-Shin, Gregg Jeff P, Lam Kit S, Guo Xiaowen
Department of Physics, University of California, CA 95616, USA.
Appl Opt. 2007 Apr 1;46(10):1890-5. doi: 10.1364/ao.46.001890.
We describe a recently developed oblique-incidence reflectivity difference (OI-RD) microscope, a form of polarization-modulated imaging ellipsometer, for label-free-high-throughput detection of biomolecular reactions on DNA and protein microarrays. We present examples of application of this technique to end-point and real-time investigations of DNA-DNA hybridization, antibody-antigen capture, and protein-small-molecule binding reactions. Compared to a conventional imaging ellipsometer based on the polarizer-compensator-sample-analyzer scheme and under the off-null condition, a polarization-modulated OI-RD microscope is inherently more sensitive by at least 1 order of magnitude to thickness changes on a solid surface. Compared with imaging surface plasmon resonance microscopes based on reflectance change on falling or rising slopes of the surface plasmon resonance, the OI-RD microscope (1) has a comparable sensitivity, (2) is applicable to conventional microscope glass slides, and (3) easily covers a field of view as large as the entire surface of a 1 in. x 3 in. (2.54 cm x 7.62 cm) microscope slide.
我们描述了一种最近开发的斜入射反射率差（OI-RD）显微镜，它是偏振调制成像椭圆偏振仪的一种形式，用于对DNA和蛋白质微阵列上的生物分子反应进行无标记高通量检测。我们展示了该技术在DNA-DNA杂交、抗体-抗原捕获以及蛋白质-小分子结合反应的终点和实时研究中的应用实例。与基于起偏器-补偿器-样品-检偏器方案的传统成像椭圆偏振仪相比，在非零条件下，偏振调制的OI-RD显微镜对固体表面厚度变化的固有灵敏度至少高1个数量级。与基于表面等离子体共振下降或上升斜率处反射率变化的成像表面等离子体共振显微镜相比，OI-RD显微镜（1）具有相当的灵敏度，（2）适用于传统显微镜载玻片，（3）能够轻松覆盖面积达1英寸×3英寸（2.54厘米×7.62厘米）显微镜载玻片整个表面的视野。
