Ultra-Content Screening (UCS): Toward the Big Blood Picture
We present Ultra-Content Screening (UCS), a novel, scalable method combining cyclic immunostaining with high-dimensional image-based single-cell proteomics. UCS utilizes fluorescein isothiocyanate-conjugated antibodies and iterative staining-photobleaching cycles to analyze up to 40 markers in up to 100,000 peripheral blood mononuclear cells per experiment. Through precise image registration, nuclear segmentation, signal harmonization, and normalization, UCS ensures the robust tracking of individual cells across all staining cycles. Data analysis via SPADE trees allows qualitative evaluation of expression patterns and cellular phenotypes. Application to samples from acute myeloid leukemia patients demonstrates UCSs potential to uncover disease-specific expression profiles and immune subpopulations. The method provides unprecedented depth in single-cell proteomic analysis of blood samples, offering valuable insights for diagnostics, personalized medicine, and therapeutic approaches.