Low-temperature, heat-mediated antigen retrieval (LTHMAR) on archival lymphoid sections

The conventional heat-mediated antigen-retrieval techniques (HMAR) using high-temperature retrieval in a variety of settings yield excellent results, but section morphology can be severely damaged. Low-temperature heat-mediated antigen retrieval techniques (LTHMAR) partly overcome this problem, but no antigen-retrieval solution has been used successfully on archival lymphoid sections cut onto uncoated slides. We report on the use of a simply prepared solution that not only produces antigen retrieval comparable to that found with HMAR, but also preserves morphology to such an extent that it can be applied to archival and contemporary lymphoid sections cut onto uncoated slides. This has allowed our laboratories to demonstrate antigens in sections that have hitherto been "out of bounds" to HMAR. We foresee this technique as being a valuable extra tool, particularly for those workers with archival lymphoid sections and, because of the gentle nature of the antigen retrieval, as a solution of great use to those working in areas of breast, skin, and gastrointestinal tract pathology where preservation of morphology can be difficult to achieve with conventional HMAR. The drawback is the discovery of one epitope looked at in this study, which degrades over a number of years in stored sections.