References:
A. Bax, G.M. Clore and A.M. Gronenborn (1990) J. Magn. Reson. 88 425-431. (Link to Article)
E.T. Olejniczak, R.X. Xu and S.W. Fesik (1992) J. Biomol. NMR 2 655-659. (Link to Article)

Minimum labelling: ¹⁵N, ¹³C

Dimensions: 3

Magnetisation is transferred from the side-chain hydrogen nuclei to their attached ¹³C nuclei. This is followed by isotropic ¹³C mixing and finally transfer back to the side-chain hydrogen atoms for detection.

This spectrum is used for side-chain assignment. It yields strips at each carbon frequency in the side chain in which all side-chain hydrogen resonances are visible. The HCCH-COSY is a slightly less crowded version in which only the hydrogen resonances of the own and neighbouring carbons are visible. Note that the spectrum is usually displayed in such a way that the ¹H detected dimension is shown along the y-axis rather than the x-axis. This means that the peaks belonging to one side-chain appear in a vertical strip rather than a horizontal strip.