Phase-shift presaturation for water peak suppression in biomolecular NMR experiments

The phase-shift presaturation technique for water suppression is further improved with effective phase cycling. In the two-dimensional NMR COSY, NOESY and HMQC experiments of biosamples, the water sup-pression factor reaches the order of 10 , making it possible to detect 13C NMR signals in extremely diluted (2 mmol/L) aqueous solutions.