Immunohistochemistry-On-a-Chip Technology for Breast Cancer Diagnosis

This paper presents a microfluidic immunohistochemistry (IHC) platform for accurate histopathological diagnoses using numerous specific biomarkers simultaneously. Breast cancer is a heterogeneous disease with many biological subtypes, and it is difficult to accurately monitor the treatment response of the disease as well as to predict the clinical outcome of individual neoplasms. We recently succeeded in developing a microfluidic interface that enables multiplexed IHC measurements on breast tissue samples. The device consists of a poly(dimethylsiloxane) (PDMS) microfludic layer with four parallel channels, which is simply pressed onto the tissue slide. Consequently, four biomarkers, such as estrogen receptor, human epidermal growth factor receptor 2, progesterone receptor and Ki-67, were examined simultaneously on human breast cancer tissues including needle biopsy. This new IHC platform has improved performance concerning assay time, consumption of tissue, antibodies and staining compounds, sensitivity, specificity and costeffectiveness. The similar microfluidic platform has also been applied for quantitative proteomic profiling in breast cancer samples. Proteomic profiling via immunocytochemistry (ICC) was examined for four breast cancer cell lines. The device enabled 20 ICC assays on a biological specimen at the same time and could be used to quantitatively compare the expression level of each biomarker.