University of Malta 1 article published in JoVE Bioengineering Optimization of a Multiplex RNA-based Expression Assay Using Breast Cancer Archival Material Shawn Baldacchino1, Christian Saliba2, Jeanesse Scerri3, Christian Scerri3, Godfrey Grech1 1Department of Pathology, Faculty of Medicine & Surgery, University of Malta, 2Centre for Molecular Medicine and Biobanking, University of Malta, 3Department of Physiology & Biochemistry, Faculty of Medicine and Surgery, University of Malta Nucleic acid degradation in archival tissue, tumor heterogeneity, and a lack of fresh frozen tissue specimens can negatively impact cancer diagnostic services in pathology laboratories worldwide. This manuscript describes the optimization of a panel of biomarkers using a multiplex magnetic bead assay to classify breast cancers.