A structure preservation of biological and organic samples, close to native state, can only be reached by cryo immobilization techniques. Cryo immobilization allows not only to preserve the high structural integrity but also to arrest dynamic processes in the μs- ms range.After freezing the sample and preparing the surface of interest, it is important to prevent the sample from ice crystal damage, removal of structural water, condensation of water or other contaminants until imaging. Therefore, ideally the samples are kept below the recrystallisation temperature of water (< 147K) during the transfer from the preparation environment into the imaging chamber.For the transfer of frozen samples several concepts have been followed in the,past: a) the specimen after manipulation/preparation were submersed in liquid nitrogen and transferred to the cold stage of the microscope or b) a preparation chamber was permanently attached to the microscope column allowing the direct transfers between the preparation chamber and the cold stage in the microscope. These concepts allow either a high grade of flexibility combined with a high risk of contamination or to prevent contamination but combined with inflexibility. In addition the later also does not allow using the microscope during the specimen preparation procedure, nor transferring the specimen to an other imaging device.

To develop cosmetic products quickly and effectively, developers need reliable test methods for evaluating product stability. Phenomena that determine the stability of cosmetic emulsions include phase transitions taking place in the relevant application and storage temperature range. The tendency of ingredients to crystallize influences the stability of emulsions especially at low temperatures. In this article a Differential Scanning Calorimetry (DSC) was used to determine the temperature of the water/ice phase transition of the continuous water phase for oil in water emulsions. A rheological, oscillating test method was developed to measure the phase transition temperature and the results were compared with those of the DSC and standard cold storage tests. There was a correlation of the crystallization temperature of the external water phase with the storage stability at –10°C. The accompanying increase in viscosity with cold storage due to structural alteration of the emulsions could be confirmed by TEM micrographs.

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