Cell sorters separate cells by their surface proteins, and they are becoming an increasingly popular tool in immunotherapy research because they enable researchers to learn more about specific cell populations within a larger, mixed population of cells. Most researchers use a centralized resource, such as a flow cytometry core facility, to access cell sorting technology. However, as cell sorting has become more common, researchers are now running into several issues conducting experiments through an outside laboratory.
First, a core laboratory may be located in another building or area, forcing researchers to traverse long distances to reach a cell sorter, potentially exposing the cells to conditions that accelerate cell death and compromise data quality.
Second, because of the high demand for this shared resource, which operates on a fully-booked schedule to cover operational costs, it’s not uncommon for researchers to wait two to three weeks for an opening on the schedule before they can sort their cells.
In addition to long wait times, research may be further delayed if an experiment does not go as planned and requires another turn on the cell sorter, which could add two to three weeks to an experiment. Even when these delays can be avoided, other factors such as travel time, set up, and sorting (which alone can take several hours) combine to make cell sorting an all-day affair before data collection even begins.
Expediting research, eliminating delays
As Dr. Andrea Cossarizza, president-elect of the International Society for Advancement of Cytometry, can attest, scheduling time with a cell sorter and planning experiments around another lab’s schedule is difficult. To address these challenges, he has acquired a small-scale, personal cell sorter—the S3e Cell Sorter from Bio-Rad Laboratories.
One of the advantages of having a personal sorter is that it reduces the time spent moving cells from one venue to another. This eliminates research delays and lessens the impact of stressors on cell health, which improves data quality.
With a sorter on his benchtop, Cossarizza’s team can sort cells immediately. “We are working really quickly now. Within four hours, maximum, we get our results,” said Sara de Biasi, a post-doctoral scholar in Cossarizza’s laboratory.
Cossarizza has successfully used the S3e to study biomarkers that indicate response to antiretroviral therapies in HIV patients. Now, he is using the same workflow for studies in immunotherapy.
New hardware can bring change to laboratories, but Cossarizza maintains his new workflow has been very reliable, and the learning curve for the S3e has been minimal. Cossarizza said, “The software is simple. The hardware is simple.” Within half a day, “anyone, including novice users, can operate the platform.”
Less time transporting cells preserves their quality
To properly study the molecular basis of immunotherapy, and to gather an accurate sense of modifications and expression changes in immune cells following treatment, cells need to be fresh. “If you work with fresh cells, you are able to examine the true physiology of the immune system,” Cossarizza said.
Researchers who do not have cell sorters in their own laboratories must transport their samples to another laboratory—sometimes across the hall, sometimes to another city. This takes time, and the more time a cell spends outside of the body, the less viable it will be.
Once cells are removed from the perfect buffer of the body, they are exposed to changes in temperature, pH, humidity, salinity and other uncontrolled environmental factors, as well as mechanical stress, all of which can disrupt normal cell function and cause degradation.
The S3e allows Cossarizza to sort cells within minutes of their collection from patients, protecting them from these stressors. “This tool gives us the opportunity to sort cells from fresh blood. And when you are using fresh material, you cannot get better data quality,” said Cossarizza.
Cossarizza added, “It only takes five to 10 minutes for blood samples to reach the cell sorter from the clinic. I wouldn’t be able to do this if I didn’t have the S3e in my laboratory.”
The S3e’s size also enables Cossarizza to handle these cells more safely. It is so small, in fact, that it can be fit inside a safety cabinet. According to Cossarizza, this level of safety is “required when you use human samples – not only those that are known to be infected with HIV, hepatitis B, and hepatitis C, but also for samples whose infectivity is not yet been determined.”