Accurate measurement of force and displacement with optical tweezers using DNA molecules as metrology standards
Accurate measurement of force and displacement with optical tweezers using DNA molecules as metrology standards
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DOI：
10.1063/1.4871005
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发表时间：
2014-04-07
影响因子：
4
通讯作者：
Smith, Douglas E.
中科院分区：
文献类型：
--
作者：
delToro, Damian;Smith, Douglas E.
光镊可以测量微微牛顿级的力和纳米级的位移，在生物物理和软物质物理研究中有着广泛的应用。我们以前已经表明，DNA分子可以用作计量标准，以定义这样的测量。对不同长度的两个DNA分子的力延伸测量可用于确定四个必要的测量参数。在这里，我们表明，确定这些参数的准确性可以提高超过7倍，通过将测量的DNA过度拉伸过渡，并使用多步骤的数据分析程序。这种方法的结果在非常强大的和精确的拟合DNA力延伸测量蠕虫状链模型。我们通过DNA拉伸，DNA解链和微球接触力的独立测量来验证准确性。(C)2014 AIP Publishing LLC.
Optical tweezers facilitate measurement of piconewton-level forces and nanometer-level displacements and have broad applications in biophysics and soft matter physics research. We have shown previously that DNA molecules can be used as metrology standards to define such measurements. Force-extension measurements on two DNA molecules of different lengths can be used to determine four necessary measurement parameters. Here, we show that the accuracy of determining these parameters can be improved by more than 7-fold by incorporating measurements of the DNA overstretching transition and using a multi-step data analysis procedure. This method results in very robust and precise fitting of DNA force-extension measurements to the worm-like chain model. We verify the accuracy through independent measurements of DNA stretching, DNA unzipping, and microsphere contact forces. (C) 2014 AIP Publishing LLC.