stronger magnet than the third in its upper compartment and attracts more
weakly magnetized cells, etc., until, at the last-but-one stage the strongest
magnet of all captures the cells with the fewest receptors. The final stage also
has no magnet and will contain any remaining completely unmagnetized cells
after the final transfer. In the presence of gravity, uncaptured cells settle into the
lower cavities by gravitational sedimentation if the transfer times are made
sufficiently long. In the absence of gravity, uncaptured cells would remain in
both the upper and lower cavities at each transfer. However, continued mixing
with each transfer would have the effect of removing the uncaptured cells in
each cavity.
This method can separate both particulate (cells) and soluble (proteins)
separands. The electromagnetic method for separating solute molecules resembles the magnetically stabilized fluidized adsorption bed developed by Noble
and co-workers [36, 37]. The separand will bind to magnetized chromatography
beads, and these will be drawn to the upper chamber by the electromagnetic field.
If the binding is due to specific affinity, then K will be very high, as non-binding
solutes will be quickly diluted away by subsequent transfers.
A comprehensive mass-balance model of multistage separation has been
developed [42]. Figure 4 graphically represents how the multistage separator is
equivalent to a tall separation column.
The electromagnetically-assisted separation process was employed by modifying a multistage technology previously developed ADSEP. The ultimate
objective is to design and fabricate a prototype of a multistage electromagnetic
separator for purifying cells and proteins. The combination of these two innovative technologies promises to provide a unique new method for performing
cell and particle separations and meeting a growing commercial demand.
In order to establish the feasibility of multistage electromagnetic separation,
the following technical objectives were addressed:
1. Determination of how closely a theoretical model can predict the outcome of
an electromagnetically-assisted separation.
2. Optimization of magnetic field, stirring procedure, and magnet design to
capture magnetized cells and particles.
3. Resolve if (and how) the existing multistage configuration may need to be
altered to accommodate the electromagnetic separation process.
4. Establish the effectiveness of separating and classifying model particles and
model cells in a multistage process, which has magnets of gradually increasing strength at each successive stage.
5. Determine optimal number of cavities to accommodate various degrees of
separation in the electromagnetic separation process.
6. Evaluate user requirements, applications, and commercial potential for a
multistage electromagnetic separator.
A preliminary concept for magnetic separation (MAGSEP) has been developed
and the feasibility of the concept was established.
MAGSEP is designed to operate based on separation governed by particle
migration rates rather than static binary separations. Due to the non-static
nature of MAGSEP, there is no equilibrium point constant or partition coef150
K.S.M.S. Raghavarao et al.
weakly magnetized cells, etc., until, at the last-but-one stage the strongest
magnet of all captures the cells with the fewest receptors. The final stage also
has no magnet and will contain any remaining completely unmagnetized cells
after the final transfer. In the presence of gravity, uncaptured cells settle into the
lower cavities by gravitational sedimentation if the transfer times are made
sufficiently long. In the absence of gravity, uncaptured cells would remain in
both the upper and lower cavities at each transfer. However, continued mixing
with each transfer would have the effect of removing the uncaptured cells in
each cavity.
This method can separate both particulate (cells) and soluble (proteins)
separands. The electromagnetic method for separating solute molecules resembles the magnetically stabilized fluidized adsorption bed developed by Noble
and co-workers [36, 37]. The separand will bind to magnetized chromatography
beads, and these will be drawn to the upper chamber by the electromagnetic field.
If the binding is due to specific affinity, then K will be very high, as non-binding
solutes will be quickly diluted away by subsequent transfers.
A comprehensive mass-balance model of multistage separation has been
developed [42]. Figure 4 graphically represents how the multistage separator is
equivalent to a tall separation column.
The electromagnetically-assisted separation process was employed by modifying a multistage technology previously developed ADSEP. The ultimate
objective is to design and fabricate a prototype of a multistage electromagnetic
separator for purifying cells and proteins. The combination of these two innovative technologies promises to provide a unique new method for performing
cell and particle separations and meeting a growing commercial demand.
In order to establish the feasibility of multistage electromagnetic separation,
the following technical objectives were addressed:
1. Determination of how closely a theoretical model can predict the outcome of
an electromagnetically-assisted separation.
2. Optimization of magnetic field, stirring procedure, and magnet design to
capture magnetized cells and particles.
3. Resolve if (and how) the existing multistage configuration may need to be
altered to accommodate the electromagnetic separation process.
4. Establish the effectiveness of separating and classifying model particles and
model cells in a multistage process, which has magnets of gradually increasing strength at each successive stage.
5. Determine optimal number of cavities to accommodate various degrees of
separation in the electromagnetic separation process.
6. Evaluate user requirements, applications, and commercial potential for a
multistage electromagnetic separator.
A preliminary concept for magnetic separation (MAGSEP) has been developed
and the feasibility of the concept was established.
MAGSEP is designed to operate based on separation governed by particle
migration rates rather than static binary separations. Due to the non-static
nature of MAGSEP, there is no equilibrium point constant or partition coef150
K.S.M.S. Raghavarao et al.