Non Uniform Sampling (NUS) is a fully integrated acquisition and processing feature since TopSpin 3.0. It allows routine use and is available for to all kinds of NMR experiments. An automatically generated and optimized NUS sparse list defines the sampling pattern leading to the fractional data acquisition. Multi-dimensional decomposition then allows to calculate the missing data points enabling a regular Fourier Transform processing of the complete data set, all done in a fully automatic fashion.
NUS removes a time barrier for high-resolution multidimensional NMR spectroscopy and is especially useful for multi-dimensional experiments in biomolecular NMR, where time savings up to a factor of 4 in 3D experiments or 10 and even more in 4D and 5D experiments can be achieved. With NUS, new protein structure determination experiments now become feasible.
Small molecule applications based on 2D spectra can also benefits from an accelerated acquisition by a factor of 2. Of special interest here are improvements in spectral resolution and quality delivered by NUS without the need to increase the overall acquisition time.
The setup and execution of NUS experiments is covered by the TopSpin license. This includes also the processing of 2D spectra. Processing of 3D – 5D NUS spectra requires additional license.
NUS implementation in TopSpin results from a research collaboration with Prof. Orekhov and co-workers. NUS in TopSpin 3.0 benefits from proven algorithms and programs such as NUS-Sampler and MDDNMR (Orekhov, V.Y., I. Ibraghimov, and M. Billeter, J. Biomol. NMR, 2003. 27(2):p. 165-173)
Non Uniform Sampling (NUS) is a fully integrated acquisition and processing feature of TopSpin