Mounting Pollen on a Thermoplastic Adhesive for Scanning Electron Microscopy

A heat-sensitive adhesive, Tempfix®, developed for scanning electron microscopy of powders and small particles, provides consistently high-quality secondary imaging with a variety of pollen grain morphologies and preparation protocols. Tempfix® was used successfully under all combinations of these conditions: (1) pollen air-dried from ETOH or artificially dried; (2) pollen transferred to naked or sputter-coated Tempfix®; and (3) pollen transferred to solid (at room temperature) or tacky (40-43° C) Tempfix®. In contrast to other adhesives, Tempfix®: (1) does not react with the dehydration fluid ethanol; (2) permits control of depth of pollen penetration into the adhesive; (3) provides a high pollen retention rate with both air-dried and artificially dried preparations; and (4) has a smooth glassy background.