Abstract
Observations made by phase contrast microscopy have been reported for the effects of formalin fixation, freezing-thawing, and freezing-drying on tissue culture fibroblasts. The fibroblasts appeared somewhat shrunken after formalin fixation, and the cellular structures appeared to be more clearly delineated. A granular cytoplasm and "brilliant" nuclei were observed. Freezing-thawing resulted in minimal change, but paraffin embedding and deparaffinization had a marked effect on the intracellular morphology. Similar studies were made on frozen-dried tissues with and without paraffin infiltration. Fresh frozen-dried sections prepared at –40° in a cryostat had structures which appeared to be more distinct than those from sections of paraffin embedded tissues prepared at –40° in the Glick-Malmstrom apparatus; however, the former frequently contained distorted areas.