Du Xiao-Guang, Fang Zhao-Lun
Research Center for Analytical Sciences, Northeastern University, Shenyang, China.
Electrophoresis. 2005 Dec;26(24):4625-31. doi: 10.1002/elps.200500274.
A simple and robust static adsorptive (dynamic) coating process using 2% hydroxyethylcellulose was developed for surface modification of poly(methyl methacrylate) (PMMA) microfluidic chips for DNA separations, suitable for usage over extended periods, involving hundreds of runs. The coating medium was also used as a sieving matrix for the DNA separations following the coating process. Four consecutive static treatments, by simply filling the PMMA chip channels with sieving matrix once every day, were required for obtaining a stable coating and optimum performance. The performance of the coated chips at different phases of the coating process was studied by consecutive gel electrophoretic separations with LIF detection using a PhiX-174/HaeIII DNA digest sample. The coated chip, with daily renewal of the sieving matrix, showed high stability in performance during a 25-day period of systematic study, involving more than 100 individual runs. The performance of the coated chip also remained almost the same after 3 months of continuous usage, during which over 200 separations were performed. The average precision of migration time for the 603-bp fragment was 1.31% RSD (n = 6) during the 25-day study, with a separation efficiency of 6.5 x 10(4) plates (effective separation length 5.4 cm).
开发了一种简单且稳健的静态吸附（动态）涂层工艺，使用2%的羟乙基纤维素对聚甲基丙烯酸甲酯（PMMA）微流控芯片进行表面改性，用于DNA分离，适用于长时间使用，可进行数百次运行。涂层介质在涂层过程后也用作DNA分离的筛分基质。为了获得稳定的涂层和最佳性能，需要连续进行四次静态处理，即每天只需一次用筛分基质填充PMMA芯片通道。通过使用PhiX-174/HaeIII DNA消化样品进行连续凝胶电泳分离并结合LIF检测，研究了涂层芯片在涂层过程不同阶段的性能。在为期25天的系统研究中，涉及100多次单独运行，每天更新筛分基质的涂层芯片在性能上表现出高稳定性。在连续使用3个月期间，涂层芯片的性能也几乎保持不变，在此期间进行了200多次分离。在为期25天的研究中，603-bp片段迁移时间的平均相对标准偏差（RSD）为1.31%（n = 6），分离效率为6.5×10⁴塔板（有效分离长度5.4 cm）。
