Spragg S P, Barnett W A, Wilcox J K, Roche J
Biophys Chem. 1976 Jul;5(1-2):43-53. doi: 10.1016/0301-4622(76)80025-7.
An analytical system consisting of an analytical cantrifuge coupled 'on-line' to a computer was assembled and tested. Collection of records from up to 9 solutions was achieved through programmes which sum readings to reduce noise as well as controlling the positioning of the scanner. With this system it was found that the limit on accuracy for molecular weights at concentrations less than 0.01 g cm-3 was +/- 3% estimated from sedimentation equilibrium experiments. The same system was used to collect records for similar concentrations from velocity experiments by employing a scanning schlieren. In this case the accuracy in estimating sedimentation coefficients was similar to those found when measuring photographs. Since the collection yields detailed information about the shape of the sedimenting boundary, the centroids of the boundary were routinely computed by second moment analysis rather than relying on the position of the maximum of the schlieren peak. In the same analysis estimates of diffusion coefficients were made routinely by calculating corrected height/area ratios for each scan. These calculations were made during the real-time of the experiment, so making available molecular parameters rather than records which must be evaluated some time after stopping the experiment.
组装并测试了一个由与计算机“在线”连接的分析离心机组成的分析系统。通过将读数求和以降低噪声以及控制扫描仪定位的程序，实现了从多达9种溶液中收集记录。使用该系统发现，根据沉降平衡实验估计，浓度小于0.01 g cm-3时分子量的准确度极限为±3%。通过使用扫描纹影仪，同一系统用于从速度实验中收集类似浓度的记录。在这种情况下，估计沉降系数的准确度与测量照片时的准确度相似。由于收集得到了有关沉降边界形状的详细信息，边界质心通常通过二阶矩分析计算，而不是依赖纹影峰最大值的位置。在同一分析中，通过计算每次扫描的校正高度/面积比，常规地进行扩散系数的估计。这些计算在实验实时进行，从而可以得到分子参数，而不是必须在实验停止后某个时间进行评估的记录。
