Figure 1.

(A) Spin polarizations of electrons (“e”), ¹H, ¹³C and ¹⁵N nuclei in a 3.35 Tesla DNP polarizer near liquid helium temperature, compared to spin polarizations of ¹H, ¹³C and ¹⁵N in a 14.1 Tesla (600 MHz) spectrometer at 273–373 K. An approach to hyperpolarization is the transfer of electron spin polarization to nuclei near 1.2 K prior to dissolution of the hyperpolarized sample in hot aqueous buffer; (B) resultant hyperpolarized samples in aqueous solutions achieve spin polarizations P that are ∼3–4 orders of magnitude enhanced relative to the thermal equilibrium polarization in an NMR spectrometer.