Quantification of oestrogen receptors in breast cancer: radiochemical assay on cytosols and cryostat sections compared with semiquantitative immunocytochemical analysis.

A radiochemical oestrogen receptor assay on cytosol was correlated with a radiochemical and an immunohistochemical oestrogen receptor assay using cryostat sections from 50 breast cancer specimens. Oestrogen receptors were reliably quantitated in 6 micron cryostat sections with Scatchard analysis using radiolabelled oestradiol, and a good quantitative and qualitative relation with cytosol oestrogen receptor assay was found. Parallel sections were used for routine histological tissue verification and for direct comparison with immunohistochemistry for oestrogen receptor.

Progesterone receptor quantification with radiolabeled promegestone (R 5020) in frozen sections of endometrium and breast cancer tissue.

A technique for the determination of the progesterone receptor content at sections was developed. Series of coverglass-mounted unfixed frozen sections were incubated with [3H]R5020 only, to determine total binding, or with excess unlabeled R5020, to determine non-specific binding. Ligand binding in the tissue sections was measured by liquid scintillation counting after repeated washing of the coverslips.

Radiochemical determination of estrogen receptors in cryostat sections of target tissues.

A radioreceptor assay on unfixed cryostat sections has been developed. Mounted and dried sections were incubated with radiolabeled estradiol in the absence and presence of an excess of diethylstilbestrol and washed with buffer. Binding of radiolabel to sections was measured by direct liquid scintillation counting.