as well as on phase demixing rates. Hence, there is a need for systematic investigation for the fractionation of mixtures of cells, selective differential
partitioning of macromolecules, and phase demixing in multistage electrophoretic extractors and counter current distribution electrophoretic extractors.
7
Conclusions
Separation technology is one of the most complex and important areas of biotechnology. It had been estimated that downstream processing accounts for
40% or more of the added value of a fermentation product [1]. Some of the new
separation technologies, which show considerable promise for the near future,
for the effective extraction of cells, particles, and macromolecules are presented
in the present review. It is encouraging to note that some successful applications
of magnetic extraction are commercialized [148]. Advanced Magnetics,
Cambridge, MA is making large super paramagnetic particles for cell
separation [38, 39] and a few companies have commercialized single-stage
magnetically assisted separators [35]. There are enough indications that
electrophoretic extraction will also soon reach the market. For example,
commercial electrophoretic separation of cells and particles has already been
carried out by the Bender and Hobein Company by its VaP series free flow
electrophoretic separators, and apparatus for proteins is commercially available
[170]. Electrokinetic demixing and electroextraction appear to overcome the
main drawbacks of ATPE, namely slow rate of phase demixing and selectivity
and control over the partitioning behavior of the desired biomolecule.
Unfortunately, information in the literature on the engineering aspects of these
field-assisted extraction methods involving heat and mass transfer is scant or
remains proprietary, and only a few reports are available.
Magnetic and electrophoretic extraction techniques are undoubtedly complementary to other methods that are in use at present in the area of biotechnology. Furthermore, they could be attractive alternatives, especially in the
cases of dilute solutions and suspension systems, where other conventional
methods normally tend to fail. The use of magnetic and electrophoretic extraction methods often results in relatively faster and more selective separation of
the target cells and macromolecules [1].
Some of the important aspects on which future research efforts need to be
focused in these areas are suggested in the present review article. In order to
develop effective field-assisted separation processing methods, an interdisciplinary effort involving a combination of physical, chemical, and engineering
aspects is very essential. Although enough attention has been paid to the
physical and chemical aspects, the engineering aspects have been largely
neglected. Mathematical modeling, which is highlighted in this review, will be
of immense use in predicting the amount of cells or macromolecules extracted
without the measurement of an inordinately large number of parameters and,
hence, due importance should be given to this aspect.
The scope of possible applications of magnetic and electrophoretic extraction methods is very broad and obviously not limited only to those discussed in
Multistage Magnetic and Electrophoretic Extraction of Cells, Particles and Macromolecules
185
partitioning of macromolecules, and phase demixing in multistage electrophoretic extractors and counter current distribution electrophoretic extractors.
7
Conclusions
Separation technology is one of the most complex and important areas of biotechnology. It had been estimated that downstream processing accounts for
40% or more of the added value of a fermentation product [1]. Some of the new
separation technologies, which show considerable promise for the near future,
for the effective extraction of cells, particles, and macromolecules are presented
in the present review. It is encouraging to note that some successful applications
of magnetic extraction are commercialized [148]. Advanced Magnetics,
Cambridge, MA is making large super paramagnetic particles for cell
separation [38, 39] and a few companies have commercialized single-stage
magnetically assisted separators [35]. There are enough indications that
electrophoretic extraction will also soon reach the market. For example,
commercial electrophoretic separation of cells and particles has already been
carried out by the Bender and Hobein Company by its VaP series free flow
electrophoretic separators, and apparatus for proteins is commercially available
[170]. Electrokinetic demixing and electroextraction appear to overcome the
main drawbacks of ATPE, namely slow rate of phase demixing and selectivity
and control over the partitioning behavior of the desired biomolecule.
Unfortunately, information in the literature on the engineering aspects of these
field-assisted extraction methods involving heat and mass transfer is scant or
remains proprietary, and only a few reports are available.
Magnetic and electrophoretic extraction techniques are undoubtedly complementary to other methods that are in use at present in the area of biotechnology. Furthermore, they could be attractive alternatives, especially in the
cases of dilute solutions and suspension systems, where other conventional
methods normally tend to fail. The use of magnetic and electrophoretic extraction methods often results in relatively faster and more selective separation of
the target cells and macromolecules [1].
Some of the important aspects on which future research efforts need to be
focused in these areas are suggested in the present review article. In order to
develop effective field-assisted separation processing methods, an interdisciplinary effort involving a combination of physical, chemical, and engineering
aspects is very essential. Although enough attention has been paid to the
physical and chemical aspects, the engineering aspects have been largely
neglected. Mathematical modeling, which is highlighted in this review, will be
of immense use in predicting the amount of cells or macromolecules extracted
without the measurement of an inordinately large number of parameters and,
hence, due importance should be given to this aspect.
The scope of possible applications of magnetic and electrophoretic extraction methods is very broad and obviously not limited only to those discussed in
Multistage Magnetic and Electrophoretic Extraction of Cells, Particles and Macromolecules
185