We have developed a tissue microarray (TMA)-based quantitative fluorescence image analysis (QFIA) method in which protein markers on TMA sections were labeled by immunofluorescence using tyramide signal amplification and a quantitative fluorescence detection system. Using this method, BRCA1 protein expression patterns were studied in the TMA sections of cell lines with known levels of BRCA1 expression and in a small group of human tissue samples obtained from sporadic epithelial ovarian cancers, their corresponding adjacent dysplastic fields, and distant non-tumor areas. We detected distinctive BRCA1 expression patterns in high-grade and low-grade sporadic epithelial ovarian cancers and their associated adjacent dysplastic fields. However, such patterns of expression could not be adequately detected by traditional immunohistochemical staining methods. TMA-QFIA provides a sensitive, automated, and quantitative measurement of protein expression on archived tissue and cell samples and will be a useful tool for protein-level molecular profiling analyses.