OMAP-28: Organ Mapping Antibody Panel (OMAP) for Multiplexed Antibody-Based Imaging of Heart with CODEX, v1.0

OMAP-28 was developed for CO-Detection by indEXing (CODEX) imaging using the Akoya Biosciences PhenoCycler system on<br>human formalin fixed paraffin embedded (FFPE) heart samples. Antigen retrieval was performed by heating the samples in<br>Dako Target Retrieval Solution (pH 9) in a high-pressure cooker for 20 minutes. To reduce tissue autofluorescence,<br>slides were treated with a solution of 4.5% hydrogen peroxide (H₂O₂) and 20 mM sodium hydroxide (NaOH) in PBS,<br>followed by photoirradiation using broad-spectrum LED light sources for two 45-minute cycles. Full protocol details<br>are provided in Ahn et al. 2024. The antibody panel includes 38 antibodies and the nuclear marker DAPI for image<br>registration and cell segmentation. Cell membrane markers such as Sodium-Potassium ATPase, CD45, and vimentin, along<br>with DAPI, were used for segmentation and annotation of individual cells. This OMAP provides spatial context for 26<br>anatomical structures and 14 cell types as listed in the ASCT+B Heart table v1.5 (Lin, Halushka, and Boppana 2024). It<br>captures all major cardiac cell types including atrial and ventricular cardiomyocytes, vascular and lymphatic<br>endothelial cells, vascular smooth muscle cells, pericytes, lymphocytes, macrophages, fibroblasts, adipocytes,<br>mesothelial cells, and Schwann cells. Markers for specialized pacemaking regions (sinoatrial and atrioventricular<br>nodes) are also included. Although subtypes of immune cells and cell states are not fully represented, future updates<br>may expand on these components.<br><br>**Bibliography:**<br><br>* Ahn, Kyung J., Shovik Bandyopadhyay, Anusha Thadi, and Kai Tan. 2024. “Phenocycler-Fusion Staining Protocol For FFPE Tissue,” January. https://www.protocols.io/view/phenocycler-fusion-staining-protocol-for-ffpe-tiss-c8cyzsxw.<br>* Lin, Shin, Marc Halushka, and Avinash Boppana. 2024. “Heart (v1.5) Graph Data, v1.5.” https://lod.humanatlas.io/asct-b/heart/v1.5/.