Sodium chloride fixation of tissues under field conditions in tropical countries.

Fixation of skin and lymph node fragments in anhydric sodium chloride at room temperature for periods of weeks or months was found to preserve morphological structures and immunoreactivity. Fragments of a size of 6-8x6x6 mm were dried and placed in anhydric sodium chloride powder in sealed containers. Prior to further processing, the specimens were desalinated and rehydrated, then snap-frozen, sectioned, fixed in acetone and stained with monoclonal antibodies. The intensity of staining of molecular structures did not differ from that of primarily snap-frozen specimens. The method allows fixation of tissues under field conditions in tropical countries and at places lacking freezing facilities.