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HelpEstrogen/Progesterone Receptor (Paraffin), Immunoperoxidase Stain
Performing Laboratory
Billings Clinic LaboratoryMethodology
Labeled-Streptavidin Biotin Immunoperoxidase StainThis test is frequently used for detection of estrogen receptors (ERs) and progesterone receptors (PRs) in breast carcinomas when decisions on hormonal therapy must be made. It is infrequently used for other tissue specimens. It can be used to detect the presence of ERs and PRs in any fixed, paraffin-embedded tissue specimen.
Specimen Requirements
1 paraffin block.Note: The performance and quality of immunohistochemical stains for formalin-fixed, paraffin-embedded tissue is critically dependent on proper fixation of tissue specimens. Immunohistochemical staining of steroid hormone receptors is especially sensitive to fixation conditions. For optimal results, tissue specimens with maximum dimensions of 1 x 1 x 0.4 cm must be fixed for a minimum of 6 hours and a maximum of 18 hours in fresh, neutral-buffered formalin. The formalin solution must be <1 month old. Tissue that cannot be immediately processed for paraffin-embedding should be transferred to 70% ethanol for storage after fixation for 18 hours in formalin.