Autoclaving epitope retrieval with

The following hydrated autoclave method can be employed for immunohistochemical detection of molecules in both cultured cell and tissue specimens. The method was used, for example, to localize androgen receptor in cultured LNCaP cells (derived from prostatic carcinoma metastasized to lymph node) and biopsy specimens from patients with prostatic carcinoma (Ehara et al 1996). After being removed from the culture medium, the cells on plastic cover slips are fixed with 10% formalin for 10 min at 20°C. Tissue specimens are fixed for 1-2 days and embedded in paraffin. Sections (5 pan) are cut, mounted on glass slides, and heated in an oven for 1 hr at 42°C to promote adherence to the slide. After deparaffmizing and rehydration, the sections are subjected to epitope retrieval treatment as follows. 

Despite some successes with the above pretreatments, the development of wet heat-induced epitope retrieval (HIER) procedures, which involves heating the fixed tissue sections in dilute metal-salt or buffer solutions at or above 100°C, for several minutes to 1/2 h, was the critical breakthrough in paraffin section immunohistochemistry (2, 7-9). Today, there are many variations of the original HIER technique. These differ primarily in the recommended buffer solutions and/or the source or mode of heating, but the basic formula of wet heat treatment over a fixed time period is similar. The most popular HIER technologies use microwave ovens, stainless steel or plastic pressure cookers, autoclaves, vegetable steamers or water-baths as the heat sources and low molarity buffers with acidic or alkaline pH (8,9,11-14). 

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