[vc_row][vc_column][vc_column_text]Monoclonal antibodies (mAbs) are often used in the diagnosis and treatment of many diseases
such as cancer. Monoclonal antibodies are produced from immune cells that are clones of a unique
parent cell. The mAbs are generated by fusing B cells (isolated from an immunised mouse) with an
immortal myeloma cell line. The resultant fused cells, known as hybridomas produce the antibodies. The
hybridomas are screened to select a clone that has the most desired antibody specificity. The products of these individual clones are monoclonal antibodies.

Isolation of single cells in monoclonal antibody production is an important step. The limiting
dilution technique is one of the most common methods in this application, which involves the principle
of serial dilution. The goal is to dilute the cell suspension to a point where only a single cell is isolated
into a single microwell. In this technique, the seeding density is very crucial. If a low seeding density is used, this will increase the number of empty wells which resulted in a waste of time and consumables.

Conversely, if the cells are seeded at a higher density, there will be a higher chance of having multiple
cells in one well, and cannot be guaranteed that the obtained clones originated from single cells as it is
difficult to identify by microscope. Therefore, limiting dilution is usually performed a few times in order to
achieve good efficiency to produce a good monoclonal cell line.

CellGem – a Novel Microfluidic-based Technique for Single Cell Isolation

Here, we describe a new method for single-cell isolation. CellGem, is a disposable chip in which
single cells can be isolated, validated, and expanded to form monoclonal cell colonies using
conventional micropipettes and microscopes.

CellGem is a simple, easy-to-use microfluidic chip that requires minimum reagent consumption.
The chip is composed of 60 arrays of wells, with the cell capture wells up one side of the chip and the
cell culture wells on the other side. Simply, the cell suspension is loaded on the chip and the cells with
the desired size will fall into the capture well, while other uncaptured cells will be washed off. The chip
is then flipped over to allow the captured single cells to drop into the culture well. The single cells are
then cultured in these wells to form single-cell colonies before harvesting and transferring to the
conventional culture ware. Due to the microfluidic system, the single cell can be cultured for a longer
time with a higher viability rate.

Principle for single-cell isolation using CellGem 

This innovative microfluidic chip-based method for the isolation of monoclonal cell lines is cost-and
time-effective and is a better alternative approach to limiting dilution or fluorescence-activated cell
sorting (FACS) which requires specialized equipment.

Check out our related blog on “The 7 Single Cell Isolation Techniques”

References

• AtlantisBioscience. THE 7 SINGLE CELL ISOLATION TECHNIQUES. 14 July, 2022. URL: The 7 Single
  Cell Isolation Techniques – ATLANTIS BIOSCIENCE
• Yeh CF, Lin CH, Chang HC, Tang CY, Lai PT, Hsu CH. A Microfluidic Single-Cell Cloning (SCC) Device for the Generation of Monoclonal Cells. Cells. 2020;9(6):1482. Published 2020 Jun 18.
  doi:10.3390/cells9061482

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