An all-in-one epitope retrieval buffer was developed to solubilize molten paraffin. This study illustrates that common all-in-one buffer additives such as surfactants and wetting agents do not solubilize molten paraffin but a water-soluble organic solvent (WSOS) does. This study also shows that the WSOS does not negatively impact immunohistochemical staining reactions. The addition of a WSOS into an all-in-one epitope retrieval buffer formulation maintains paraffin in solution when slides mounted with tissue sections are removed from the buffer. This action is an advantage for buffer tanks in which slides are in a vertical orientation; the slides are not recoated with molten paraffin.

The Thermo Scientific Fast Flex ® tissue processing system was designed to offer a flexible methodology and to provide high quality tissue processing results within a same-day tissue processing time frame. This reagent system was originally developed to work exclusively on the Thermo Scientific STP 420D tissue processor. To increase flexibility for the end user, we have developed protocols that are compatible with the Pathcentre tissue processor. Three sets of sister sections, from a variety of human tissues, were examined for lesions or areas of interest, then representative smaller samples were selected for processing. These sections were processed via one of three methods: overnight protocol and conventional reagents using a routine tissue processor, Fast Flex ® tissue processing system using the STP 420D, or Fast Flex ® tissue processing system using the Thermo Scientific Pathcentre. This study compares the processing protocols between the three methods, illustrates the resulting tissue morphology, provides examples of immunohistochemical work, and outlines workflow opportunities. ( The J Histotechnol 32(4): [179][180][181][182][183][184][185] 2009)