Modifications of embedding tissues in durcupan ACM (Fluka) based on viscosity index measurements.

Viscosity of Durcupan ACM mixtures without as well as with accelerator was measured, at temperatures of 25, 40, and 50 degrees C respectively. The time course of polymerization was expressed within first few hours following admixture of accelerator, at temperature mentioned above. On the basis of our findings a modified embedding schedule for tissues (peripheral autonomic nerves and ganglia) has been recommended: infiltration in Durupan 1 (without accelerator) could be performed at 50 degrees C, when viscosity of embedding mixture is greatly reduced, to 190 mPa. s. Further infiltration in Durcupan 2 (with accelerator added) is carrier out at 40 degrees C; the initial viscosity of embedding medium at this temperature is 440 mPa. s. and even after 4 hours it keeps below 200 mPa. s. So the infiltration time could be prolonged in contrast to that at 50 degrees C, which usually brings better embedded blocks and better ultrathin sections.