Biochemists using this technique rely on bi·celles, bi·layers, or bacterio·phages to establish a rhombic alignment tensor. This experimental technique is used to compute a protein’s Saupe tensor, its random coil index, and an order parameter symbolized “capital S squared.” This technique is the gold standard for real-time measurement of RNA and protein folding ensembles. During refinement, this technique provides both distance and angular constraints by combining a through-space measurement of cross-polarization with residual dipolar couplings. Unlike cryo-E·M or crystallography, this (10[1])technique provides protein structures in solution through experiments like HSQC (10[2])or NOESY (10[8])(“nosy”). Before (10[2])analysis by this technique, (10[1])samples are labeled with odd-mass isotopes (10[1])like nitrogen-15 (10[1])or carbon-13. For 10 (10[1])points, name this form of spectroscopy in which (10[1])nuclear spins (10[1])are (10[1])flipped (10[2])in a magnetic field. ■END■ (10[2]0[1])