Hayem's is common reagent that used in red blood cell counting. it consist of HgCl2, NaSO4 and NaCl. Why that composition can be eliminate another cell blood without affecting red blood cell?
The solutions for RBC manual counting (including Hayem's solution) are used to preserve the integrity of cellular membrane and it have no effect on leukocytes that are not eliminate. The effect of the presence of leukocytes on RBC counts is deleted by the dilution factor that is equal to 1:100 or more. Because this fact the presence of leukocytes on the Thomas or Burker cameras is negligible.