Osmotic Fragility Test (OFT)
A measure of the RBCs resistance to haemolysis by osmotic stress, depending primarily on the volume of the cell, the surface area and the cell's membrane function
RBCs are incubated in varying concentrations of a hypotonic solution of sodium chloride (NaCl)
As the concentration of NaCl decreases, cells take on water to produce osmotic equilibrium
Normal cells begin to haemolyse at NaCl concentrations of approximately 0.50%
Because of their Dec. surface area:volume, spherocytes can not expand as much as normal discoid cells, thus lysis is usually completed by 0.4-0.5%, starting at higher NaCl concentrations
Incubation of blood overnight at 37oC makes the OFT more sensitive
A measure of the RBCs resistance to haemolysis by osmotic stress, depending primarily on the volume of the cell, the surface area and the cell's membrane function
RBCs are incubated in varying concentrations of a hypotonic solution of sodium chloride (NaCl)
As the concentration of NaCl decreases, cells take on water to produce osmotic equilibrium
Normal cells begin to haemolyse at NaCl concentrations of approximately 0.50%
Because of their Dec. surface area:volume, spherocytes can not expand as much as normal discoid cells, thus lysis is usually completed by 0.4-0.5%, starting at higher NaCl concentrations
Incubation of blood overnight at 37oC makes the OFT more sensitive
ليست هناك تعليقات:
إرسال تعليق