微流控芯片最初起源于分析化学领域，是一种采用精细加工技术，在数平方厘米的基片，制作出微通道网络结构及其它功能单元，以实现集微量样品制备、进样、反应、分离及检测于一体的快速、高效、低耗的微型分析实验装置。随着微电子及微机械制作技术的不断进步，近年来微流控芯片技术发展迅猛，并开始在化学、生命科学及医学器件等领域发挥重要作用。本文首先简单介绍了微流控芯片制作材料和工艺，然后主要阐述了其在蛋白质分离、免疫分析、NDA分析和测序、细胞培养及检测等方面的应用进展。

设计并制备了一种新的具有分子探针功能的主体分子型非病毒载体-邻菲啰啉-β-环糊精衍生物主体分子（DZY-1），应用凝胶电泳法研究探讨了DZY-1与DNA相互作用及客体分子对该主体分子诱导DNA凝聚的影响；并进一步研究探讨了单一主体分子、主/客体分子配合物诱导DNA分子凝聚和聚合所形成的超分子聚合物抗限制性内切酶（HindⅢ）酶解的特性. 应用扫描电子显微镜（SEM）观测到该主体分子、主/客体分子配合物与DNA分子相互作用形成超分子聚合物的微观结构形态。阐述了其作为非病毒基因载体可能的传递机制，为设计、制备新的非病毒基因载体提供了一种新途径。

Condensation of DNA by multivalent cations can provide useful insights into the physical factors governing the folding and packaging of DNA in vivo. In this work, local ordered structures of spermidine-DNA complexes prepared from different DNA concentrations have been examined by using atomic force microscopy (AFM) and polarizing microscopy (PM). Two types (I and II) of DNA condensates, significantly different in sizes, were observed. It was found that for extremely dilute solutions (DNA concentrations around 1ng/ml or below), the DNA molecules would collapse into toroidal structures with a volume equivalent to a single l-DNA (type I). In relatively dilute solutions (DNA concentrations between 1 and 10ng/ml), a significantly larger structure of multimolecular toroids (circular and elliptical, type II) were formed, which were constructed by many fine particles. Measurements show that the average diameter of these fine particles was similar to the outer diameter of the monomolecular toroids observed in extremely dilute solutions, and the thickness of the multimolecular toroids had a distribution of multi-layers with height increments of 11 nm, indicating that the multimolecular toroidal structures have lamellar characteristics. Moreover, by enriching the DNA-spermidine complexes in very diluted solution, branch-like structures constructed by subunits were observed by using AFM. The analysis of the pellets in polarizing microscopy reveals a liquid-crystal-like pattern. These observations suggest that DNA-spermidine condensation could have multiple stages, which are very sensitive to the DNA and spermidine concentrations.