Prevention of Evaporation Caused by a Rapid Immunohistochemistry Method Applying Non-contact Alternating-Current Electric-Field Mixing

Abstract

It is widely recognized that pathology is the most important factor for staging and selecting effective chemotherapy for patients with cancer. Immunohistochemistry (IHC) is a reliable screening method, but intra-operative diagnosis by frozen section with IHC is not possible because IHC takes approximately 6 hours. We recently developed a rapid-IHC method that makes use of an alternating current (AC) electric field to facilitate the antigen-antibody reaction, and reported its usefulness for detection of lung cancer and breast cancer. The antibody is mixed within microdroplets as the voltage is switched on and off at specific intervals. The resultant Coulomb force stirs the diluted solution on the sections, which increases the opportunity for contact. The rapid-IHC device reduces the time required for IHC as well as the amount of antibody required for analyses. The device may also be applied for in situ hybridization (ISH); however, ISH requires a warm temperature, such as 37℃, and a longer processing time than the rapid-IHC method. Consequently, evaporation can be a problem during ISH. The aim of the present study was to evaluate the utility and reliability of an oil cover and cover cap made of polyethylene terephthalate (PET) for preventing evaporation due to the AC electric field applied to facilitate the antigen-antibody reaction. We have shown that both the oil cover and PET cover cap prevented evaporation when using the rapid-IHC device.