Cell Line Development
The Chinese hamster ovary (CHO) cell line is widely used for the production of therapeutic antibodies. In a typical cell line development workflow, CHO cells are transfected with an IgG expressing vector. Single transfected CHO cells are isolated for clonal expansion and high titer clones are identified via ELISA following outgrowth. These high producing cell lines are then expanded for large scale antibody production.
Generating cell lines for therapeutic antibodies requires clonal cell populations. Isolation of single cells for CHO cloning has traditionally been done with either FACS or limiting dilutions, each of which have inherent drawbacks.
Fluorescence-Activated Cell Sorters (FACS)
sort cells at very high pressure (up to 70 psi), which is harsh on the cells and results in reduced cell viability. These machines are also very difficult to use and prone to cross-contamination and clogging.
while gentler than FACS, is time-consuming, labor-intensive, and has very poor single cell isolation efficiency (by the Poisson distribution, empty wells and doublets are guaranteed). Therefore, this approach is extremely inefficient and costly.
CHO cells are transfected with a plasmid encoding the desired protein for mass production. Following selection, transfected cells in suspension are loaded into one of Namocell’s proprietary microfluidic cell cartridges and dispensed with Namocell’s Single Cell Dispenser into 96- or 384-well plates for clonal outgrowth. Following clonal expansion, colonies are analyzed via ELISA to determine antibody titers.
Gentle sorting (< 2 psi) preserves cell viability Higher clonality, better outgrowth
Easily isolate high titer CHO clones
Dispense single cells into 96-well plate in 1 min, or 384-well plate in 6 min
Fit inside a cell culture hood for sterile sorting No clogging, no cross-contamination; Easy to use, zero maintenance
Namocell Single Cell Dispensers are highly efficient and consistent at dispensing single cells (80-90% with mammalian cells) compared to manual pipetting (~30%).
Namocell’s Namo Single Cell Dispenser was used to sort CHO cells for clonal outgrowth alongside both limiting dilution (LDC) and a FACS. Cells sorted with Namo showed higher cloning efficiencies than LDC and FACS.
What Scientists are Saying
Here at Cytovance, we love our Namocell. This machine has increased our plating capacity and efficiency nearly four-fold. The accuracy of Namocell’s 384-well plating coupled with the easy changes between samples has been a game changer for our workflow.
Namocell Hana single cell dispenser provides a great solution for gentle single cell cloning using sterile disposable cartridges. The system is easy to use and quick to initialize. Hana combines the advantages of FACS and microfluidic cell dispensing to enable high assurance of monoclonality with high throughput and great cell viability.
We’ve been using the Namo to do single cell sorting for genomics/ transcriptomics applications as well as for colony selection for tissue culture. We’re overall very satisfied with our results and find the setup to be very easy, as well as standard maintenance. After sterility protocols (which can take an hour), being able to immediately jump to sorting in less than ten minutes has saved us time and precious samples.
The Hana has had a positive impact on our workflow. We are now able, with a high degree of confidence, to generate clonal populations of cells with reduced cytotoxicity (compared to FACS) while simultaneously saving hands-on time due to not needing to immediately screen for single cells after manual limited dilutions. In many cell lines, we see a significantly higher efficiency of clonality from plate to plate compared to our previous methods.
The instrument works very well for our purposes of single-cell dispensing, primarily gene-edited lines. Easy to use; the setup and dispensing time is very short. It has the benefits of a FACS machine (binning by forward/side scatter), with lower pressure to help increase cell survival.
Namocell’s disposable cartridges have allowed us to increase the throughput of the validation of our CRISPR engineered cell lines since we can sort a full plate in less than 3 minutes, and can move to the next plate without the hassle of cleaning. This outstanding product is paired with Namocell’s exceptional customer service that has been responsive and attentive to our needs. While evaluating different FACS machines, we simply did not find a rival that combined Namocell’s simplicity, performance and value, all while occupying a small footprint.
Our stem cell core facility was looking for ways to speed up our human induced pluripotent cell cloning to generate clonal cell lines and to analyze our gene editing efficiencies in single cells. Our criteria for an instrument for single cell dispensing was 1) sterility, 2) gentle on cells, 3) ease of use, and 4) reasonable cost. The Namocell fitted our criteria perfectly. We are able to reduce the time and effort for generating clonal CRISPR-engineered iPSC lines significantly. The instrument requires very little maintenance and users do not need to be highly trained with the main requirement being good aseptic technique. We are excited to use the Namocell potentially for other single cell applications.