The Single-probe SCMS has coupled with fluorescence microscopy to investigate cell-cell interactions. Chen et al. employed the technique in a co-culture system, which included drugresistant and drug-sensitive cancer cells, to study metabolism affected by cell-cell interactions (Figure ). Two types of co-culture systems were studied, including indirect (two different types of cells were cultured in the same well but separated by Transwell) and direct (two different types of cells were directly cultured in the same well without separation) co-culture systems. In the direct co-culture experiments, one type of cells was labeled with GFP (green fluorescence protein), and fluorescence microscopy was combined with the Single-probe SCMS to analyze metabolites of single cells in each group. The study revealed that drug-sensitive cells exhibited increased resistance and altered metabolic profiles when co-cultured with drug-resistant cells, shedding light on the role of cellular communication in the development of chemotherapy resistance. This application demonstrated the integration of SCMS, and microscopy techniques could provide unique insights into the metabolic shifts driven by cell-cell interactions, paving the way for future studies on the metabolic responses of heterogeneous cell populations. The Single-probe SCMS has also been coupled with bright field microscopy to study cell heterogeneity. Nguyen et al. extended the application of SCMS to infectious diseases by investigating host cell heterogeneity during Trypanosoma cruzi (T cruzi) infection, the causative agent of Chagas disease (CD) . The study revealed significant metabolic differences between infected cells, which contain stained parasites, and uninfected cells as well as the presence of bystander effect, which indicates uninfected cells adjacent to infected ones displaying altered metabolism. The bystander effect suggested a novel mechanism for lesion development in parasitefree areas, offering crucial insights into the pathogenesis of CD. This work represents the first use of SCMS in studying mammalian-infectious diseases, showcasing the technique's broad applicability beyond cancer research.