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Posted on Mon, May 26, 2014

Magnetic cell separation processes in 3 steps

Cell separation is widely used in research and clinical therapy. For research purposes, sorting cells from a heterogeneous population enables the study of the different isolated types. From a therapeutic perspective, cell separation allows for the introduction of enriched cell populations to a patient. Moreover, the latest advances in stem cell therapy, tissue engineering and regenerative medicine shows the potential of cells derived from different tissues. The use of highly selective separation procedures is critical to improve the quality of these cell-based treatments.

If you are interested in cell isolation with biomagnetic separation, download our newest guide Does it matter which magnetic separation rack I use in my cell isolation processes?:

Free PDF guide:  "Magnetic Separation Racks for Cell Sorting"

Steps of biomagnetic separation in cell isolation

Biomagnetic cell separation is an alternative to centrifugation, columns, filtration and precipitation. It is usually faster and simpler, and eliminates undue cell-stress and reduces the risk of negative impact on cell function and phenotype.

The three basic steps for magnetically separate cells using are:

  1. Magnetic beads are added to a cell-sample, which is then incubated. The magnetic beads then attach to cells via antibodies, pectin or other substances. If the right biomarker is selected, only the desired cells are labeled.  
  2. When these labeled cells are placed with the entire mixed-cell population into a Biomagnetic Separation system, the targeted cells are pulled by magnetic force, separating them from the cell culture with the attached beads.  
  3. Once the separation is complete (typically, few minutes), non-labelled cells are extracted with the remaining supernatant. Only the labelled cells are retained

Separation can be positive by labeling the cells targeted for analysis or culture. Unlabeled cells are then pipetted out and discarded. Alternatively, negative separation labels unwanted cells which are left in the retention device and the supernatant is extracted without them.

But there are also disadvantages...

In spite of the numerous types of magnetic beads available, the process does not always work as well as it should. Sometimes, recovery is poor due the lack of magnetic force farther from the magnet. Another typical problem is when cells are crushed by excessive retention force. Moreover, scaling-up the process over few milliliters seems impossible. Most of these problems are not related to the beads or the biomarker, but to the separation rack. All the great efforts made to select the right markers and magnetic beads to ensure their correct attachment to the desired cells goes to waste if the wrong magnetic separation rack is used.

Figure 1 Cell isolation

To ensure optimal performance of the magnetic beads selected to capture and separate cells, the value and profile of the magnetic force should be carefully selected to ensure high recovery rates and gentle retention. We will discuss how the different magnetic force profile affects the cell separation process in two next weekly posts.

Remember to download our newest guide Does it matter which magnetic separation rack I use in my cell isolation processes? if you want to know everything about this topic.

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