STABILISATION AND LYOPHYLISATION OF PROTEINS DURING FREEZING-DRYING FOR HISTOLOGICAL PURPOSES

The influence of the water content in frozen-dried tissues for the quantitative and qualitative preservation of proteins was investigated experimentally by means of immunoflorescence methods. It is shown, that a minimal water content must remain so that a mild heat fixation can occur. When sections of absolutely dried tissues are incubated with immunofluorescent reagents, the proteins are extracted and therefore no or very weak reactions will be seen. On the other hand, a too high water content will cause heavy denaturations of proteins during the embedding in paraffin so that immunological and enzymatical activities are abolished, inspite the fact that these proteins are quantitatively well preseved. - Up to this moment the achivement of appropriate water content in frozen dried materials is a matter of empirism. © 1969 Springer-Verlag.