We discuss the feasibility of multiplex QD stain for four biomarkers and our progress in finding four suitable biomarkers from four different hosts. There is a demand for using more than three fluorescent probes on a single tissue sample for disease detection to offer a more reliable prediction of disease progression. We developed a protocol for targeting four biomarkers using four primary antibodies from four different animal hosts. We performed primary-secondary antibody binding assays on nitrocellulose paper and stained breast cancer microarray slides with known expression of ER, PR, and HER2. We identified the lack of a standard protocol and the limited supply of primary antibodies from hosts other than rabbit and mouse in the market as key challenges. The results show variable success in both assays, but indicate future potential for this protocol with more development.