Methods of Cell Separation

A cell sorter is a machine that can categorize cells into categories according to similar characteristics. Modern cell sorters can analyze several thousand cell particles in a few seconds. These machines can be helpful in cell separation, which is commonly used in diagnosing diseases. Cell separation is most commonly used in determining cancerous cells in the blood, but is used in other areas of research as well. There are different cell separation methods that can be used in research.

Cell Sorting

The cell sorting process is typically done right after the flow cytometry or the identification of cells using fluorescent probes or magnetic labeling by using magnetic tags. Cell sorting uses the isolation and separation of specific cell populations from a sample. After the cells are identified with a flow cytometer, the cells are vibrated at the frequency of the cell of interest. Certain cell groups share internal frequencies, which cause them to form into droplets according to their fluorescent profile and size. The drops are processed through an electric field and the cell type of interest is singled out and saved for additional studies. The cell sorter at Bayer College of Medicine in Houston performs this function.

Immunomagnetic Cell Separation

Immunomagnetic-based cell sorting is extremely popular in the medical field because of its efficiency, availability, and its high purification. However, it does have some disadvantages due to limited capacity to remove unnecessary cell types from the sample. This drawback is due to the sorter's ability to single out and remove cells with a low number of receptors. Immunomagnetic cell sorting is similar to cell sorting but uses immunological reactions to purify samples such as cancer cells.

Deterministic Lateral Displacement

Northern University in Boston uses deterministic lateral displacement, which is another method of size-based cell sorting. This method involves a microfluidic device that continually separates cell sub-populations. All the cells that vary in size will pick a route through the device that results in high resolution.

Microfluidics

Another method of cell separation is by passing an electromagnetic gradient through a particle-based microfluidic that is used at the University of California, Los Angeles. Microfluidics are types of fluids that can be monitored and isolated to small parameters. When microfluidics are combined with cell separators, it enables the output of the separator to be better monitored. This cell separation method has many advantages, including higher magnetic forces and lower costs less than other cell separation methods.

References

• Northeastern University: Size-based cell sorting by deterministic lateral displacement; Deepa Sritharan; 2009.PDF
• Ohio State University: Immunomagnetic cell separation: further applications of the quadrupole magnetic cell sorter; Oscar R. Lara-Velasco; 2003
• University of California, Los Angeles: Cell Separation Device Using High Electromagnetic Gradients Through a Particle-Based Microfluidic Approach; Yuh Lin; 2007
• Bayer College of Medicine: Cytometry and Cell Sorting Facility; 2011