Abstract 1044: Low-cost, high-sensitivity InSituPlex® mIF assays on the Parhelia Omni-Stainer™

Abstract Background: Multiplex immunofluorescence (mIF) is an important tool for extracting complex phenotypic information from normal or diseased tissues, and provides accurate and predictive insights on the tissue microenvironment faster. For patient samples in translational and clinical research, high sensitivity, specificity, and reproducibility are critical; however, throughput and cost considerations are also important in designing clinical studies. Enabling an easy-to-use high-performance assay such as InSituPlex® on robust and affordable auto-stainers like the Parhelia Omni-Stainer™ can allow researchers to gain a deeper understanding of the tissue micro-environment through high-quality multiplexed biomarker detection in a fraction of the time and cost. Methods: We performed Ultivue InSituPlex® assays with OmniVUE™ panels using the Parhelia Omni-Stainer™, a low-cost, high-throughput tissue auto-stainer with reduced requirements for reagents with a minimal dead volume. We compared the whole-slide staining performance across replicates using human tonsil and tumor tissue arrays across multiple independent runs over multiple days. The stained slides were scanned using the Zeiss AxioScan. Z1 high-throughput imaging system, and image batches were processed using Ultivue’s UltiStacker. AI and UltiAnalyzer. AI software. Results: Tighter temperature control of the slide in the Omni-Stainer supports optimal InSituPlex® signal amplification. Intra-run and inter-day analysis on serial sections of human tonsil and tumor tissue arrays demonstrated a high degree of consistency in InSituPlex® assay performance, specifically with marker-specific signal intensities and cell densities. The Omni-Stainer facilitates the use of low reagent volumes at each step of the assay due to its efficient reagent use, thus lowering the cost of reagents per slide. Conclusions: This study demonstrated a fast, simple and robust workflow to perform high-performance InSituPlex® mIF assays on the low-cost, high-throughput Parhelia Omni-Stainer™. Ultivue’s configurable OmniVUE™ mIF panels can be run on the Omni-Stainer with reduced associated reagent costs per slide. This workflow can support larger clinical and translational studies in a more cost-effective fashion, leading to in-depth analysis of tissue microenvironment through highly precise multiplexed biomarker detection. Citation Format: Kevin Hwang, Lauren Duro, Alex Veith, Nelson Wedin, Nikolay Samusik, Je H. Lee. Low-cost, high-sensitivity InSituPlex® mIF assays on the Parhelia Omni-Stainer™ abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 1044.