The objective of the proposed research is to develop a clinical-trial-ready device and to evaluate its practical utility as a routinely used intra-operative tool. Our multidisciplinary group has previously shown that optical techniques can effectively discriminate between malignant and non-malignant breast tissues. The proposed technology will be a multi-channel optical assay device for intra-operative imaging of margins in specimens excised from patients undergoing breast conserving surgery (partial mastectomy) or mastectomy.