With an increasing interest in both immunological procedures and elemental (ion) detection, it is imperative that tissues be preserved in as life-like a state as possible. Up until now the only type instrument available for in situ cryo fixation was various configurations of cryopliers which lacked the ability to control freezing variables. With the introduction of the PS1000 (Delaware Diamond Knives, Inc.), a pneumatically operated hand held slammer, it is now possible to reproducibly fix in situ as well as in vitro and achieve results seen previously only with table top instruments. This instrument is designed to provide a consistent delivery rate through the use of a pneumatically operated piston.

The availability of such an instrument, clearly improves the accuracy of many investigations. Pleural fluid of the lung parenchyma (Figure 1) has been preserved in its natural state (i.e., filled with air). Figure 2 shows a proximal tubule of rat kidney which has been crycgenically preserved in situ. Applications in biological research, materials science and clinical pathology are currently being investigated at several major institutions.