Water-bath developers formulas

Anhydrous Ethyl Ether. This is for those formulas calling for dry, pure, or anhydrous ether. The ether product from above is dried over thin slices of metallic sodium (metallic sodium wire works well also) for 24 hours. Then the ether is distilled on a water bath, over fresh (fresh means a different batch than what you used to dry with) metallic sodium. Note Ether develops explosive peroxides upon sitting for any length of time, even if just purchased from a supply house. Therefore, before handling ether, which has been stored, shake with ferrous sulphate or with lead peroxide. To keep peroxides from forming in fresh ether add several sections of copper or iron wire to the dark container and store in a cool place. 

All three of the famous Weston s—Edward, Brett, and Cole—used amidol paper developer formulae. Each had his own variation. All four of the following formulae are used undiluted and should be followed by running water or a citric acid stop bath. 

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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