Rapid extraction and screening of high-purity DNA fragments is an indispensable technology in advanced molecular biology. In this article, mesoporous magnetic composite microspheres (MSP@mTiO₂) with tunable pore sizes were successfully fabricated for high-purity DNA extraction and fragment screening. Owing to the strong complexation ability of Ti ions with DNA phosphate groups and the high specific surface area of mesoporous microspheres, the MSP@mTiO₂ microspheres possess excellent adsorption performance, where the saturated loading capacity of MSP@mTiO₂ with a specific surface area of 122 m² g⁻¹ is as high as 575 μg mg⁻¹ for a salmon sperm specimen. ITC experiments demonstrated that DNA adsorption on MSP@mTiO₂ microspheres is mainly driven by entropy, which gives us more potential ways to regulate the balance of adsorption and desorption. Meanwhile, the mesoporous MSP@mTiO₂ microspheres exhibit a much higher extraction efficiency compared with non-porous MSP@TiO₂ for whole genome DNA from Arabidopsis thaliana plants. Interestingly, DNA fragments with different lengths could be screened by simply regulating the pore size of MSP@mTiO₂ or the concentration of Na₃PO₄ in the eluent. A small pore size and low phosphate concentration are advantageous for the extraction of short-stranded DNA fragments, and DNA fragments (≤1000 bp) can be efficiently extracted when the mesopore size of MSP@mTiO₂ is lower than 7.6 nm. The extraction results from the mesoporous composite microspheres provide new promising insights into the purification and screening of DNA from complex biological samples.

中文翻译：

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具有受控介孔壳的磁性复合微球，用于高效 DNA 提取和片段筛选

高纯度DNA片段的快速提取和筛选是先进分子生物学中不可或缺的技术。在本文中，成功制备了孔径可调的介孔磁性复合微球（MSP@mTiO ₂ ），用于高纯度DNA提取和片段筛选。由于Ti离子与DNA磷酸基团的强络合能力以及介孔微球的高比表面积，MSP@mTiO ₂微球具有优异的吸附性能，比表面积的MSP@mTiO ₂的饱和负载量为对于鲑鱼精子样本来说，122 m ² g ^-1高达 575 μg mg ^-1 。 ITC实验表明，MSP@mTiO ₂微球上的DNA吸附主要是由熵驱动的，这为我们提供了更多潜在的方法来调节吸附和解吸的平衡。同时，与无孔MSP @TiO _{2相比，介孔MSP@mTiO 2}微球对拟南芥植物全基因组DNA的提取效率更高。有趣的是，只需调节MSP@mTiO ₂的孔径或洗脱液中Na ₃ PO ₄的浓度就可以筛选不同长度的DNA片段。小孔径和低磷酸盐浓度有利于短链DNA片段的提取，当MSP@mTiO ₂介孔孔径小于7.6 nm时，可以有效提取DNA片段（≤1000 bp）。介孔复合微球的提取结果为从复杂生物样品中纯化和筛选 DNA 提供了新的有前景的见解。