DNA and buffers: Are there any noninteracting, neutral pH buffers?
DNA and buffers: Are there any noninteracting, neutral pH buffers?
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DOI：
10.1006/abio.2000.4848
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发表时间：
2000-12-01
影响因子：
2.9
通讯作者：
Righetti, PG
中科院分区：
文献类型：
--
作者：
Stellwagen, NC;Bossi, A;Righetti, PG
已通过自由溶液毛细管电泳分析了DNA与各种中性pH、基于胺的缓冲液的相互作用，使用质粒大小的DNA分子和小DNA寡核苷酸的混合物作为报告系统。这两种DNA在20-80 mM TAE（TAE，Tris-乙酸-EDTA; Tris，三[羟甲基]氨基甲烷）缓冲液中以单独的、接近高斯形的峰迁移。峰之间的分离随着TAE缓冲液浓度的增加而逐渐增加，这是因为大DNA分子和小DNA分子之间的溶剂摩擦的差异。这两种DNA在TEE（Tris-borate-EDTA）缓冲液中与硼酸根离子形成复合物，其迁移率取决于DNA/硼酸根比率。在45 mM TEE缓冲液中，两种DNA共迁移为单个尖锐峰，其迁移率比相同缓冲液中的任一种组成DNA快。因此，混合的DNA-硼酸盐复合物通过结合额外的硼酸盐离子而稳定，可能在不同的DNA之间形成桥。通过增加TEE浓度，混合的DNA-硼酸盐复合物逐渐解离成其组分DNA，这可能是因为硼酸盐结合位点在高缓冲液浓度下变得饱和。其他中性pH、基于胺的缓冲液，如Mops（N-[N-吗啉代]丙磺酸）、Hepes（N '-[2-羟乙基]哌嗪、N'-[2-乙磺酸]）、Bes（N，N-双[2-羟乙基]-2-氨基乙磺酸）、Tes（N-三[羟甲基]甲基-2-氨基乙磺酸）和tricine（N-三[羟甲基]甲基甘氨酸）也与DNA形成复合物，在电泳图中产生扭曲峰。综合结果表明，硼酸盐缓冲液和大多数中性pH，基于胺的缓冲液与DNA相互作用。(C)北京大学出版社.
The interaction of DNA with various neutral pH, amine-based buffers has been analyzed by free solution capillary electrophoresis, using a mixture of a plasmid-sized DNA molecule and a small DNA oligonucleotide as the reporter system. The two DNAs migrate as separate, nearly Gaussian-shaped peaks in 20-80 mM TAE (TAE, Tris-acetate-EDTA; Tris, tris[hydroxymethyl]aminomethane) buffer. The separation between the peaks gradually increases with increasing TAE buffer concentration because of differences in solvent friction between large and small DNA molecules. The two DNAs form complexes with the borate ions in TEE (Tris-borate-EDTA) buffer, with mobilities that depend on the DNA/borate ratio. In 45 mM TEE buffer, the two DNAs comigrate as a single sharp peak, with a mobility that is faster than either of the constituent DNAs in the same buffer. Hence, the mixed DNA-borate complex is stabilized by the binding of additional borate ions, possibly forming bridges between the different DNAs. The mixed DNA-borate complex is gradually dissociated into its component DNAs by increasing the TEE concentration, possibly because the borate binding sites become saturated at high buffer concentrations. Other neutral pH, amine-based buffers, such as Mops (N-[N-morpholino]propanesulfonic acid), Hepes (N'-[2-hydroxyethyl]piperazine,N'-[2-ethanesulfonic acid]), Bes (N,N-bis[2-hydroxyethyl]-2-aminoethanesulfonic acid), Tes (N-tris[hydroxymethyl]methyl-2-aminoethanesulfonic acid), and tricine (N-tris[hydroxymethyl]methylglycine) also form complexes with DNA, giving distorted peaks in the electropherograms. The combined results indicate that borate buffers and most neutral pH, amine-based buffers interact with DNA. (C) 2000 Academic Press.