Patent ID: 6396267
Filing Date: 2002-05-28
Classification: G01R

Abstract:
A method for performing polarization transfer in a nuclear magnetic resonance (=NMR) experiment with spin systems of large molecules, especially biological macromolecules in solution, comprising at least two kinds of spin Â½ nuclei I and S being coupled to each other, the spin system being subjected to a homogeneous magnetic field B0, being irradiated by a sequence of radio frequency (=rf) pulses comprising a first 90Â° pulse exciting the spins of the nuclei I and after a delay time a further 90Â° pulse exciting the spins of the nuclei S,characterized in thatthe sequence of rf pulses is chosen such that there is no inversion pulse acting on the spins of the nuclei S during a time period T between the first 90Â° pulse exciting the spins of the nuclei I and either the further 90Â° pulse exciting the spins of the nuclei S or a second 90Â° pulse acting on the spins of the nuclei I, and that the length of the time period T is chosen such that {square root over (sinh+L (RCT+L )2+L +sin(&pgr;JIST+L )2+L )} exp(âˆ’RIT) is maximized with respect to T, whereRC is the transverse cross-correlation-relaxation rate of nuclei I RI is the total transverse relaxation rate of nuclei I and JIs is the scalar coupling constant between nuclei I and S.