By assessing the efficiency of your cell separation methods, you can make an informed decision on which technique is best suited for your experiment. There are a variety of metrics that factor into determining efficiency. Some of the most important are cell throughput, recovery, and yield.
Cell throughput is often overlooked as an important metric in cell separation. Throughput represents the rate at which cells can be sorted in terms of the number of samples, number of cells, or sample volume. Throughput refers to how many samples your separation method can process at once, or how many cells can be isolated by a single kit or experiment. This statistic is important when handling large quantities of cells at once.
One of the best ways to save time and money is to choose a cell separation technique with high throughput—especially for smaller companies or independent researchers that need to maximize the value of their cell separation efforts. The ability to sort large populations of cells simultaneously without sacrificing other important metrics like recovery and yield is extremely beneficial when performing downstream assays.
Calculating throughput involves dividing the total number of cells that can be processed by the amount of time it takes to perform the sort. Choosing a cell separation method with a quick workflow and the ability to sort multiple samples at once allows for high throughput.
Another indicator of a good cell separation method is high cell recovery. Cell recovery is the proportion of desired cells isolated during the separation process compared to the number of desired cells available in the starting sample. Recovery measures the effectiveness of a cell separation assay. This metric will be reported as a percentage of the total desired cells from the starting sample.
Cell recovery is one of the most important aspects because it shows how successful your cell separation method is at doing what it’s supposed to. Other metrics, such as purity, measure the status of a cell sample after separation is complete with no reference to the before. Without factoring in the initial number of desired cells in a sample, there is no way to tell how many target cells were lost throughout the process.
Cell recovery alerts the scientist to target cell death or loss within a sample. The lower your recovery percentage is, the more cells were lost in the separation process. When performing downstream analysis or experimentation, you want to have as many healthy target cells as possible to increase the accuracy of results. Choosing a gentle and effective cell separation method that doesn’t result in cell death can help increase your cell recovery to optimize cell sorting efforts.
You cannot perform the recovery calculations until you recover cell populations after separation. Once you obtain the number of recovered cells and the number of initial desired cells, the percent cell recovery formula is as follows:
Where R equals Recovery:
For example, if you begin your experiment with 100,000 total cells, 20,000 of which are target cells, the recovery formula would only focus on the 20,000 target cells. After cell separation, if you had 25,000 total cells, 18,500 of which were target cells, the recovery formula would only focus on the 18,500 target cells which are still viable. Using the recovery formula, our calculation would look like this:
Where R equals Recovery:
The cell recovery of this cell separation is 92.5%. Cell yield is another metric that’s directly related to the recovery value.
Cell yield is the term for the number of desired cells recovered from cell separation or the top value of the percent recovery formula. This is usually represented as a more absolute value as opposed to a percentage. Cell yield is directly proportional to cell recovery, which means if one increases the other also increases.
In the example above the cell yield is 18,500 target cells. If the yield were 19,000 cells, the cell recovery percentage would increase from 92.5% to 95%. Thus, improving cell yield can help improve sample recovery.
Cell yield and recovery depend on many of the same factors, such as sample types, sample preparation quality, cell isolation kit quality, the initial number of cells, population safety protocols, and the heterogeneity of a starting sample. To increase the cell yield of a sample, it’s necessary to address each of these aspects.
Using a cell separation technique that’s proven to be effective at isolating gentle or fragile cells can prevent cell death to increase yield and recovery. Carefully following the protocols and directions of that technique can reduce contamination and mistakes that lead to the loss of target cells. Maximizing the number of viable desired cells for downstream assays should be a priority when choosing which cell separation method to use.
Choosing the right cell separation method will depend on the specific needs of your experiment. However, maximizing efficiency and minimizing resources spent will always benefit your overall efforts. You want a technique that offers high throughput processing without sacrificing cell recovery.
Traditional methods like magnetic bead-based sorting can be harsh on delicate cells and result in limited throughput, as larger samples often need to be aliquoted into several smaller tubes for processing. Fluorescence-activated cell sorting takes an extended amount of time for processing when the sample size is large or complex, but the time required can be greatly reduced when the sample is first enriched for the population of interest prior to sorting. Novel alternatives for enrichment, like Akadeum’s buoyancy, activated cell sorting (BACS), offer fast and easy processing that is exceptionally gentle on delicate cells of interest while increasing throughput to enable entirely new assays and workflows.
Akadeum’s novel BACS technology leverages the power of buoyancy to enable self-separation directly in the sample container. The functionalized microbubbles are simply mixed into the sample where they bind to their targets, gently floating them to the surface of the sample container for collection or removal. The microbubble workflow is easily scalable both in terms of the fluidic volume being interrogated as well as the number of samples being processed concurrently. With no harsh forces and a quick workflow that leaves the desired cells practically untouched, the microbubble approach can streamline cell separation efforts without sacrificing throughput, recovery, or cell yield.
Akadeum Life Sciences is dedicated to improving your cell separation efforts. Our microbubble technology is tailored to provide high throughput preservation of cell health and physiology. Our microbubble enrichment kits maintain cell heath and physiology during processing, allow you to sort multiple samples simultaneously, and significantly reduce hidden costs associated with traditional methods of sample preparation.