Halperin A, Buhot A, Zhulina E B
Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Université Joseph Fourier, Grenoble, France.
Biophys J. 2004 Feb;86(2):718-30. doi: 10.1016/S0006-3495(04)74150-8.
Competitive hybridization, at the surface and in the bulk, lowers the sensitivity of DNA chips. Competitive surface hybridization occurs when different targets can hybridize with the same probe. Competitive bulk hybridization takes place when the targets can hybridize with free complementary chains in the solution. The effects of competitive hybridization on the thermodynamically attainable performance of DNA chips are quantified in terms of the hybridization isotherms of the spots. These relate the equilibrium degree of the hybridization to the bulk composition. The hybridization isotherm emerges as a Langmuir isotherm modified for electrostatic interactions within the probe layer. The sensitivity of the assay in equilibrium is directly related to the slope of the isotherm. A simpler description is possible, in terms of c(50) values specifying the bulk composition corresponding to 50% hybridization at the surface. The effects of competitive hybridization are important for the quantitative analysis of DNA chip results, especially when used to study point mutations.
在芯片表面和整体溶液中的竞争性杂交会降低DNA芯片的灵敏度。当不同的靶标能与同一探针杂交时，就会发生竞争性表面杂交。当靶标能与溶液中的游离互补链杂交时，就会发生竞争性整体杂交。竞争性杂交对DNA芯片热力学可达到性能的影响，通过斑点的杂交等温线进行量化。这些等温线将杂交的平衡程度与整体组成联系起来。杂交等温线呈现为针对探针层内静电相互作用进行修正的朗缪尔等温线。平衡状态下检测的灵敏度与等温线的斜率直接相关。根据指定表面50%杂交时整体组成的c(50)值，可以进行更简单的描述。竞争性杂交的影响对于DNA芯片结果的定量分析很重要，尤其是在用于研究点突变时。
