Development of a novel immunohistochemical staining technique (PLATESTAIN technique) based on the capillary action principle

Objective.-To improve the complex manual staining methods used in immunohistochemistry, the authors invented a glass plate designed to achieve accurate immunoreaction using the capillary action principle. Materials.-This plate has slightly elevated edges and provides five narrow gaps between the reactive surfaces and glass slides. Each reactive surface is treated with a hydrophobic agent, to allow uniform antibody diffusion. Results.-Seventy-five cases of control tissues, benign neoplasms, and malignant neoplasms were immunohistochemically examined with this plate, and the staining intensity was compared with that of the conventional three-step streptavidin-biotin technique. Using this device and biotin-long spacer conjugated secondary antibody, even diffusion of antibodies and reagents and sensitive reactions could be achieved, thus making immunostaining easier and more accessible. The hydrophobic agent produced no unfavorable results. Also, the technique greatly reduced the amount of antibody, reagent, and chromogen solution required. Antigen retrieval by microwave heating of tissue sections and immunostaining of sex hormone receptors and cell proliferation markers were also successful. Conclusion.-This technique provides a great technical improvement in immunohistochemistry and eliminates the health problems and environmental hazards associated with conventional techniques.