Freeze-dried paraffin-embedded human tissue for antigen labelling with monoclonal antibodies.

Conventional fixation and paraffin embedding of human tissue destroys most of the antigens detected with currently available antibodies, while cryostat sections give poor morphological detail and require freezer space for storage. However, when tissue was freeze-dried before being embedded in paraffin S then stained for a wide range of antigens recognised by monoclonal antibodies (including T-cell and B-cell antigens), morphological preservation was clearly better, and the labelling reactions were of equal (or greater) intensity, than with cryostat sections. As the number of diagnostically important monoclonal antibodies continues to increase the use of freeze-dried paraffin sections should facilitate the introduction of immunohistological techniques for both routine histopathological diagnostic work and immunological research.