Field now fractionation (FFF) is a new methodology described as being
well-suited for the separation and characterization of biopolymers and
particles. On theoretical grounds, cells may be separated with FFF if
they differ in size, density or deformability. In the present study,
we first tried to determine optimal separation conditions for red bloo
d cells; thereafter we used FFF to examine red cell changes during a p
henylhydrazine-induced hemolytic anemia. It has been shown that in les
s than 30 minutes, FFF is able to separate normal red blood cells from
Heinz body-rich cells or reticulocytes that differ in size or density
. The successive steps of hemolysis and regeneration appear clearly on
the fractograms. Advantages and drawbacks of the method are discussed
.