Arkray R.B.C. Diluting Fluid is a colorless, clear, and isotonic solution used in hematology for the accurate counting of red blood cells (RBCs) under a microscope. It acts as a diluent for blood samples, diluting them 1:200 to prevent hemolysis, maintaining cellular integrity for reliable results, and ensuring consistent and precise analysis for diagnostic purposes. The fluid contains sodium sulphate and glacial acetic acid, among other components, standardized to maintain blood cell structure during counting with a hemocytometer.