Sysmex Stromatolyser reagents (WH, 4DL, 4DS) are specialized lysis agents used in Sysmex automated hematology analyzers to lyse red blood cells (RBCs), allowing for accurate white blood cell (WBC) counting, WBC differential, and hemoglobin measurement. They stabilize WBCs for analysis and are crucial for consistent, high-quality results in analyzers like the XS, XT, and XE series.