A new cold stage for SIMS analysis and imaging of frozen-hydrated biological samples

We have build an original cold stage, meant for the analytical imaging and the depth profiling of frozen-hydrated biological specimens by use of the S IMS method. This new equipment, associated with a CAMECA IMS 4f ion analyse r, has been used to study standard (a frozen H2O/D2O mixture) or biological samples. Although the freezing conditions used in our present case did not allow the obtaining of reliable biological data, the main following method ological results have been yielded: i) our newly developed cold stage is no w fully functional, ii) the use of freeze-fractured samples is unsatisfacto ry and iii) both for depth profiling and imaging it is possible to get acce ptable results with cryosections under neutral oxygen bombardment (FAB) or even under O-2(+) bombardment, provided that the cryosections are sufficien tly thin.