Use of the avidin-biotin-peroxidase immunostaining technique on previously stained histologic sections

A recent report has demonstrated that the avidin-biotin-peroxidase (ABP) technique can successfully be used on previously stained histologic sections without the loss of sensitivity. In this study the tissues had been microwave fixed and only H & E stained sections were used. This procedure was tested on formalin-fixed tissues previously stained with H & E, PAS and van Gieson. Stained sections were prepared from selected blocks used as controls. One week after staining the sections were decolorized and together with the unstained control sections were restained with the ABP technique using IgA, IgD, IgE, IgM, kappa and lambda light chains, S100, EMA, LCA, amylase and PCK antisera. Demonstration of the tissue antigens was best with the previously stained H & E slides with little or no loss in sensitivity. Variable results were obtained with the PAS and van Gieson slides, the loss of sensitivity varying from none to complete.