Transportable long-lived hyperpolarized samples

A method for the preparation of a hyperpolarized solution of molecules comprises the steps: 1) suspending or coating of a micro-particulate matrix, which is comprising or consisting of the molecules, with a glass-forming solution or suspension comprising a DNP-suitable polarizing agent at a first temperature at which the micro-particulate matrix is not dissolving; 2) lowering the temperature leading to a frozen glassy DNP sample; 3) transferring the electron spin polarization of the polarizing agent in the glassy sample in a magnetic field to abundant nuclear spins of the glass-forming solution or suspension and/or the polarizing agent as well as to abundant nuclear spins of the molecules and cross-polarization from the abundant nuclear spins in the molecules to one different nuclear spin type in the molecules; and 4) increasing the temperature and dissolving the molecules which are hyperpolarized with respect of the different nuclear spins.