Usefulness of Auto Cyto Fix (membrane filter method) for the application of immunohistochemistry

We developed the Auto Cyto Fix (ACF) 1000 as an experimental model, which was adapted as a membrane filter method for automatically making smear preparations fixed with 95% ethanol. In this study, immunohistochemistry was applied to the cells smeared on the membrane filter, and effectiveness was examined. Twenty-four effusions and HeLa 229 cells were used. These cell samples were produced by the ACF1000 on the membrane filter and stained by the Papanicolaou method. After observation, these were decolored and stained by immunohistochemical techniques. Antibodies included CEA, EMA, and MIB-1. CEA and EMA were detected by the indirect method, and were colored by DAB, AEC, and new fuchsin. MIB-1 was detected by the immunoperoxidase (LSAB) and the immunofluorescence method. A uniformly stabilized immunoreaction was obtained and was equivalent to or better than that of the conventional technique. In addition, there was no background staining on the membrane filter. Based on these results, the membrane filter preparation produced by the ACF1000 was also effectively applied to immunohistochemical observations.