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Introduction: Minimal residual disease (MRD) is known to be an independent predictor of progression free survival (PFS) in multiple myeloma (MM). Methods of MRD detection include flow cytometry, PCR based sequencing, and imaging. However, irrespective of the sensitivity of MRD detection, techniques based on bone marrow biopsies cannot account for a “patchy,” non-homogenous bone marrow infiltration. Positron emission tomography (PET) coupled with computed tomography (CT) using 18fluoro-deoxyglucose as the radiotracer (18FDG-PET) is a commonly used imaging method that is much more sensitive than traditional radiographs, but it has several limitations; for one, lesions with a low metabolic rate may result in false negatives. Also, diffuse tracer uptake by normal marrow can obscure focal MM lesions. Daratumumab (Dara), a human anti-CD38 IgG1(ĸ subclass) antibody against the highly expressed plasma cell receptor CD38, has been recently approved by the FDA for the treatment of MM. Based on the idea that Dara can selectively target MM cells irrespective of their metabolism, our group labeled Dara with the positron-emitting isotope copper-64 (64Cu-DOTA-Dara) in order to generate a novel imaging agent that can detect MM cells with high specificity. Our group already safely used 64Cu-labeled trastuzumab to detect HER2-positive tissue in breast cancer patients (Mortimer JE et. al. 2014), and here we provide the first pre-clinical evidence that 64Cu-labeled antibodies can be considered powerful imaging tools for MM detection.