Lou Xinhui, Qian Jiangrong, Xiao Yi, Viel Lisan, Gerdon Aren E, Lagally Eric T, Atzberger Paul, Tarasow Theodore M, Heeger Alan J, Soh H Tom
Department of Materials, University of California, Santa Barbara, CA 93106, USA.
Proc Natl Acad Sci U S A. 2009 Mar 3;106(9):2989-94. doi: 10.1073/pnas.0813135106. Epub 2009 Feb 6.
Aptamers are nucleic acid molecules that have been selected in vitro to bind to their molecular targets with high affinity and specificity. Typically, the systematic evolution of ligands by exponential enrichment (SELEX) process is used for the isolation of specific, high-affinity aptamers. SELEX, however, is an iterative process requiring multiple rounds of selection and amplification that demand significant time and labor. Here, we describe an aptamer discovery system that is rapid, highly efficient, automatable, and applicable to a wide range of targets, based on the integration of magnetic bead-based SELEX process with microfluidics technology. Our microfluidic SELEX (M-SELEX) method exploits a number of unique phenomena that occur at the microscale and implements a design that enables it to manipulate small numbers of beads precisely and isolate high-affinity aptamers rapidly. As a model to demonstrate the efficiency of the M-SELEX process, we describe here the isolation of DNA aptamers that tightly bind to the light chain of recombinant Botulinum neurotoxin type A (with low-nanomolar dissociation constant) after a single round of selection.
适体是在体外筛选出的核酸分子，能够以高亲和力和特异性与其分子靶标结合。通常，通过指数富集的配体系统进化（SELEX）过程来分离特异性高亲和力适体。然而，SELEX是一个迭代过程，需要多轮筛选和扩增，耗时费力。在此，我们描述了一种适体发现系统，该系统基于磁珠SELEX过程与微流控技术的整合，具有快速、高效、可自动化且适用于多种靶标的特点。我们的微流控SELEX（M-SELEX）方法利用了一些在微尺度下出现的独特现象，并采用了一种设计，使其能够精确操纵少量珠子并快速分离高亲和力适体。作为证明M-SELEX过程效率的模型，我们在此描述了在一轮筛选后分离出与重组A型肉毒杆菌神经毒素轻链紧密结合（解离常数为低纳摩尔）的DNA适体。
