Influence of embedding media in prolactin labelling with immunogold techniques

Immunogold labelling of prolactin in three different embedding media was compared. The polymeric prolactin in secretory granules was labelled in the three media, however, acrylic monomers (Lowicryl K4M and LR White) provided a more intense labelling with higher dilutions of the primary antibody, compared to the labelling in the epoxy resin (araldite). An intense labelling of monomeric prolactin in Golgi complex was detected only in acrylic embedments, and the labelling on the rough endoplasmic reticulum was significant only in LR White embedded tissues.