Osmotic
fragility Test
Principle:
When red cells are put in hypotonic solutions, water enters the cell
until equilibrium
is achieved. The cell swells until the internal volume is too great causing cells to burst (lyse).
Procedure:
series of 14 tubes with NaCl concentrations decreasing from 1% to 0% are set up.
patient’s blood is then added to each
tube and allowed to sit at room temp. for
30 minutes
tubes are then centrifuged and amount of hemolysis is determined