Pre-embedding epitope retrieval: an ultrasound based method for unmasking desmine in tissue blocks

GIMENO EJ; MASSONE AR; PORTIANSKY EL

APPLIED IMMUNOHISTOCHEMISTRY

LIPPINCOTT WILLIAMS & WILKINS

Lugar: Philadelphia; Año: 1998 vol. 6 p. 35 - 41

1062-3345

It has been repeatedly shown that exposure to formaldehydeproduces progressive loss of tissue epitopes. In the past fewyears, different physical methods-for example, techniquesbased on ultrasound (US), núcrowave (MW), and pressurecooker (PC) technology-have been developed for recoveringmasked antlgens and allowing immunohistochemical (IHC)SL:´lin ing. Taking into accounl that many antigens were recoveredusing these retrieval methods after deparaffination of tissuesections, we wanted to test whether it is possible to recovermuscular desmin, asan antigen model, before tissue embeddingin paraffin (i.e., preembedding epitope retrieval [PRER]). Forthis purpose, the three physical retrieval methods already mentionedwere employed and statistically compared, and a comparisonwith the conventional postembedding epitope retrieval(POER) techniques was also made. We have found that preembcddingt:reatment with MW and PC methods was entirely inappropriatefor Lhe recovery of desmin in tissue blocks, whereasthe US PRER was able tO ·unmask desmin in most formalinfixedskeletal muscle pieces and the combination of US PRERand different POER methods allowed a greater amount of desminto be unmasked. Additionally, no overheating of tissueblocks or detachment of tissue sections was observed; thus, thisapproach could be suitable to obtain enough material for hundredsof sections to work with as many unmasked epitopes aspossible in a few seconds of sonication.