Preparation of Biological Samples for Ion Microscopy

Ion Microscopy is a powerful technique for intracellular elemental localization in b specimens. The effechve w of this technique depends on the reliability of sample preparation. An ideal Sam le reparation should preserve the chemical and structural integrity of a living cell, and it shouPd ago satisfy the instrumental requirements for analysis. This article critically reviews different methods of sample preparation for diffusible element anal sis in soft biological tissues and cultured cells. Frozen freeze-dried tissue ayosections mountezon a smooth conducting substrate provide reliable specimens for ion miaosco ic anal sis. For tissue culture cells, a cry0 freeze-fracture freeze-dry method can be used for difKsible erement localization and ion transport studies. Ion images of physiologically important diffusible elements such as Ca, K, and Na are included to show their intracellular distribution in tissue sections and cultured cells. Typical sample preparation artifacts are also discussed.