Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA.
Anal Biochem. 2013 Jun 1;437(1):104-8. doi: 10.1016/j.ab.2013.02.011. Epub 2013 Feb 28.
We report systematic and large inaccuracies in the recorded elapsed time in data files from the analytical ultracentrifuge, leading to overestimates of the sedimentation coefficients of up to 10%. This far exceeds previously considered factors contributing to the uncertainty in this parameter and has significant ramifications for derived parameters such as hydrodynamic shape and molar mass estimates. The source of this error is currently unknown, but we found it to be quantitatively consistent across different instruments, increasing with rotor speed. Furthermore, its occurrence appears to correlate with the use of the latest data acquisition software from the manufacturer, in use in some of our laboratories for nearly 2 years. Many of the recently published sedimentation coefficients may need to be reexamined. The problem can be easily recognized by comparing the file timestamps provided by the operating system with the elapsed scan times recorded within the data files. Therefore, we implemented a routine in SEDFIT that can automatically examine the data files, alert the user to significant discrepancies, and correct the scan times accordingly. This eliminates errors in the recorded scan times.
我们报告了分析超速离心机数据文件中记录的流逝时间存在系统和大量的不准确，导致沉降系数的高估高达 10%。这远远超过了以前认为会导致该参数不确定的因素，并对衍生参数如流体力学形状和摩尔质量估计产生了重大影响。目前还不知道这个错误的来源，但我们发现它在不同的仪器中具有定量一致性，随着转子速度的增加而增加。此外，它的发生似乎与制造商最新数据采集软件的使用有关，我们的一些实验室在过去近 2 年中一直在使用该软件。最近发表的许多沉降系数可能需要重新检查。通过比较操作系统提供的文件时间戳与数据文件中记录的流逝扫描时间，可以很容易地识别出这个问题。因此，我们在 SEDFIT 中实现了一个例程，可以自动检查数据文件，提醒用户注意明显的差异，并相应地纠正扫描时间。这消除了记录扫描时间中的错误。
