Abstract: A qualification process for a sample to be examined by means of cryo-electron microscopy. The, sample (12) is applied to a sample carrier (10) provided for cryo-electron microscopy and subsequently the sample (12) arranged on the sample carrier is examined by means of dynamic light scattering. The particle size distribution within the sample (12) is determined by means of the dynamic light scattering. Further, a sample holder designed to carry out the qualification process.

Abstract: A method for crystallizing a substance dissolved in a solvent, including the following steps: introducing a solvent volume containing the substance into a chamber having a preset temperature, humidity, and gas composition, adding a predetermined volume of a precipitant to the solvent volume containing the substance, allowing the solvent to evaporate while simultaneously observing structural changes in the solvent volume containing the substance and the precipitant by means of dynamic light scattering, detecting weight changes and determining the molarities, making an association with the location in the phase diagram on the basis of the DLS measurement and the results of the molarity determination, allowing a predetermined number of crystal nuclei to form by adding solvent or adding precipitant, putting the solvent volume containing the substance and the precipitant into a metastable state by adding solvent and/or protein solution or by allowing the concentration of the dissolved substance to decrease by allo