In-depth understanding of the nature of cell physiology and ability to diagnose and control the progression of pathological processes heavily rely on untangling the complexity of intracellular molecular mechanisms and pathways. Currently, neither widely used conventional methods nor more advanced nanoparticle-based techniques have the capacity for achieving this goal. Multiplexing potential of reporter probes, used for detection of molecular targets of interest, is heavily restrained by the limited selectivity of target-probe pairing and lack of uniquely identifiable probes. Here we present two complementary versatile methods towards achieving comprehensive single-cell molecular profiling and describe engineering of fluorescent nanoparticle (or quantum dot) probes specifically tailored for each approach. In contrast to other methods utilizing quantum dots or other nanoparticles, which often involve sophisticated probe synthesis, the platform technology presented here takes advantage of simple covalent bioconjugation and non-covalent self-assembly mechanisms for straightforward probe preparation and specimen labeling, requiring no advanced technical skills and being directly applicable for a wide range of molecular profiling studies.
Utilization of quantum dot platform for single-cell molecular profiling promises to greatly benefit both biomedical research and clinical diagnostics by providing a tool for addressing phenotypic heterogeneity within large cell populations, opening access to studying low-abundance events often masked or completely erased by batch processing, and elucidating biomarker signatures of diseases critical for accurate diagnostics and targeted therapy.