Influence of clearing agent on immunohistochemical staining of paraffin-embedded tissue

Abstract

It is well recognised that fixation is an important factor in the determination of immunoreactivity of antigens in paraffin-embedded tissues. The effect of subsequent tissue processing has rarely been studied and the ethanol-chloroform schedule appears to be the 'routine method' when details are available. Many laboratories use xylene as their routine clearing agent, which has been shown to have an extracting quality on cell cytoplasm as seen ultrastructurally and to decrease immunoreactivity of frozen sections. The author describes a study to determine the effect of different clearing agents on subsequent immunoreactivity of fixed and embedded tissue.