Methacrylate: An alternative fixing agent for identifying the botanical origin of propolis

Premise A new technique was developed to identify the botanical origin of propolis, a resin-like material made by bees by mixing saliva and beeswax with plant buds and exudates, using methacrylate for permanent slide preparation. Methods and Results Propolis samples were fixed in methacrylate to produce permanent slides. The anatomical structures of the plant fragments in the methacrylated propolis were compared with propolis slides prepared using conventional techniques that consist of propolis sediment obtained during a series of solvent reactions, filtration, and centrifugations, which cost a similar amount to produce. The techniques resulted in qualitative differences between the slides obtained. The methacrylated propolis sections allowed the detailed observation and identification of plant anatomical structures that were obscured in samples prepared using the conventional procedure. This clarity enabled the detailed evaluation of valuable taxon-diagnostic characters in a permanent slide, which can also be used for histochemical tests. Conclusions The methacrylated embedding of propolis is an affordable technique that could be implemented as a routine laboratory procedure. This new technique enables the efficient determination of the botanical origin of propolis.