Application of a T2-filtered COSY experiment to identify the origin of slowly relaxing species in normal and malignant tissue.

The 1H NMR spectrum of whole cells consists of many overlapping resonances which are difficult to resolve into individual components. We have developed a modification of the COSY pulse sequence which filters out resonances on the basis of their T2 relaxation rate. When applied to malignant cells, this technique has helped to identify fucose as the origin of the slowly relaxing species associated with their metastatic capacity. The technique can also be used to obtain T2 relaxation rates for individual resonances in a broad envelope of lines.