Issue link: https://resources.nanotempertech.com/i/1138492
2 TECHNICAL NOTE ©2019 NanoTemper Technologies, Inc. South San Francisco, CA, USA. All Rights Reserved. Intermediate precision is also called inter-assay precision or occasionally within-lab reproducibility. It describes how similar results are when obtained within the same laboratory, by different operators, or across measurement systems. Exemplary data is shown in Figure 1. Calculated results were compared using the T i , or the point on the curve which represents unfolding of the sample, which can also serve to assess the precision of the temperature control. Raw data was compared using two parameters: first, the initial ratio, which is well-suited for this purpose as it is sensitive towards misalignments of optics and sample tray. Good repeatability data on the initial ratio measurement across the six capillaries also suggests correct alignment and adjustment of the system. The second raw data parameter tested was sample brightness, which is the combined brightness signal at 330 nm and 350 nm at 35 °C. Both raw data parameters need to be precise in order for Tycho to perform well in day-to-day applications: the initial ratio can be used as an indicator of % unfolded sample, while sample brightness can be used to assess protein concentration. Tables 1 and 2 list measured values (where applicable) along with standard deviations (SD) and relative standard deviations (RSD) for repeatability and intermediate precision. The RSD is also known as coefficient of variation (CV). The determined RSD is useful since it is dimensionless and independent of the magnitude of the measured values, which means it allows to compare different types of systems even with completely different output parameters. Conclusions Taken together, these results demonstrate that Tycho achieves excellent repeatability (intra-assay precision) and intermediate precision (inter-assay precision), making it an extremely reliable and an easy-to-validate system for every lab working with proteins. Figure 1: The figure shows exemplary data from one Tycho run. Two of the parameters used in this study, the initial ratio and the T i , are labeled. The unfolding profiles of all six capillaries overlap perfectly, as do the vertical lines indicating the T i . In this particular example run, the average initial ratio across all six capillaries was 0.910 ± 0.001 and the average T i across all six capillaries was 87.83 °C ± 0.08 °C.