Overview of Cell Separation

Cell separation is the process of removing one cell population from another within a biological sample, such as blood or tissue. It was first achieved in 1964 by S. H. Seal, who separated large tumor cells from smaller blood cells using filtration. Two years later, Pohl and Hawk performed experiments on how cells respond differently to a nonuniform electric field based on the cell type. Such observations were the inception of cell separation methods, which allow isolating a single cell type from a heterogeneous sample.

Significance of Cell Separation

• Cell separation, also commonly referred to as cell isolation or cell sorting, is a process to isolate one or more specific cell populations from a heterogeneous mixture of cells.
• Studying the capabilities of individual cells provides insight into their specific functions and roles in the body. Knowing exactly what certain cells do allows scientists to harness their capabilities and learn from them. Cell isolation is a major catalyst in advancing the ability to individualize drugs and treat large populations using effective general-purpose approaches.

Cell Separation Methods and Technologies

The choice of separation method is based on the characteristics of the cell type to be isolated, such as surface charge, cell size, density, morphology, physiology, and surface markers. Usually, one or more of these characteristics are employed to isolate the particular cell type efficiently.

• Buoyancy-activated cell sorting (BACS)
  It is a negative selection process that involves sorting cells with buoyant microbubbles. Microbubbles bind to cells, and the targeted cells are removed from the biological sample through flotation. This innovative method can be custom-tailored with a variety of bio-analytes to target specific cell groups while maintaining a high purity, yield, recovery, and viability.
• Magnetic-based cell sorting
  This is a form of immunomagnetic separation that involves binding magnetic particles to target cells through an affinity molecule/surface marker interaction. Depending on the cells being targeted, MACS can be a positive or negative selection method.
• Fluorescence-activated cell sorting (FACS)
  It is a specialized type of flow cytometry that involves labeling targeted cells with fluorescent markers and running the sample through a flow cytometer device. Then, cells are identified and sorted one by one based on the color of their markers into isolated cell populations.
• Cell separation by centrifugation
  During centrifugation, a sample is spun causing more dense particles to move to the outer edges of the mixture while less dense objects group together further in. A biological sample is centrifuged until the cell types are isolated into layers.
• Aptamer-Based Cell Isolation
  Aptamer-based cell isolation uses aptamers such as DNA or RNA to bind to targeted cells based on specific biomarkers.

Creative Bioarray Relevant Recommendations

• Creative Bioarray offers a ready-to-use density gradient medium and PBMC Isolation Kit for purifying lymphocytes in high yield and purity from small or large volumes of peripheral blood from different species. We are dedicated to delivering thoroughly tested and high-quality products that do not adversely affect cells during isolation.

Applications of Cell Separation

Isolated cells can be grown in vitro to produce cell lines, which have numerous applications in areas like pharmacology, immunology, and stem cell therapy.

• Cell separation is essential in screening for the appropriate B-cells for monoclonal antibody production.
• Single-cell analysis, such as studying gene expression patterns and epigenetic effects, also relies on the isolation of specific cells to study.
• Many oncological studies that contribute to our understanding of cancer cells require isolating particular tumor cells from the tissue.

Challenges of Cell Separation Methods

Cell separation techniques face a high noise-to-signal ratio, with a small number of specific cells (target) against a large number of varied components that form the tissue. Various factors affect the purity of the final isolate. Additionally, the population size of the target cell type in the tissue is also a limiting factor.