Rapid Embedding in Lowicryl K4M for Immunoelectron Microscopic Studies

Abstract A rapid method of embedding tissues in Lowicryl K4M was developed. The initiator was replaced with benzoin ethyl ether, and the temperature of polymerization under indirect ultraviolet light was increased from −35°C to −10°C. The complete polymerization occurred in 24 hours. Compared with the original method and two other rapid methods proposed by Altman et al. (J. Histochem. Cytochem. 32:1217–1223, 1984), the above mentioned rapid method gave more reproducible results, and the preservation of the tissues was better. The preservation of the antigenicity was excellent as tested with anti‐amylase on zymogen granules of the rat's exocrine pancreas and with anti‐zona pellucida on ova of the golden hamster. Comparison of the preservation of antigenicity by means of the new rapid method shows an increased specific labeling when using the rapid Lowicryl K4M method as compared to the original Lowicryl K4M and Epon. Background levels between the original and rapid Lowicryl K4M methods are not significantly different. However, the two Lowicryl K4M methods differ significantly when compared to Epon. The reliability of this rapid method makes it suitable for introduction not only for research but also as a routine diagnostic histochemical technique at the ultrastructural level.