Question

What does the yield of a sorting depend on?

Answer

The actual recovery percentages depend on several factors:

• Cell quality: this is the most critical factor affecting yield. Cells must be free of aggregates and in a single-cell suspension.
• Cell death before and after sorting, or loss due to adhesion to the tube walls.
• Sorting speed: the higher the speed, the lower the yield.
• Accuracy of the sorter setup.
• Whether the sorting is for enrichment or for purity: enrichment sortings typically result in higher yields.
• Losses during sample preparation.

When a user claims to have brought a sample with 1×10⁷ cells, this number should reflect the cell count after the entire preparation process, including filtration to remove aggregates.
Sorters accurately count the cells that pass through the instrument.
Therefore, if the user assumes to have brought 1×10⁷ cells but the sorter detects only 0.6×10⁷, then the actual number of cells is not 1×10⁷.

It should also be noted that a small aliquot of the sorted cells can be used to assess sorting efficiency. However, in cases of very low yield, this verification may be skipped.

That said, post-sort analysis is essential if you plan to publish the results of the experiment.

Tip: use at least 50% more cells than the theoretical number required for sorting.