Evaluation of HistoGel™-embedded specimens for use in veterinary diagnostic pathology.

HistoGel™ is an aqueous specimen-processing gel that encapsulates and suspends histologic and cytologic specimens in a solidified medium. HistoGel-embedded specimens can then be processed and evaluated by routine histologic and immunohistochemical methods. This methodology has been used in human diagnostic pathology and is especially useful for small, friable, or viscous tissue samples that are difficult to process. In addition, special histochemical stains or immunohistochemistry can be performed on HistoGel-embedded cytologic specimens using standardized methods developed for histopathology. The current report describes several applications for HistoGel, including use with cytologic specimens, bone marrow aspirates, retention of tissue orientation for endoscopic biopsy specimens, and evaluation of friable tissues. Samples were encapsulated in HistoGel, fixed in 10% neutral buffered formalin, routinely processed, paraffin embedded, and sectioned for histochemical and immunohistochemical evaluation. The results of this study support the use of HistoGel in veterinary diagnostic pathology.