ISolate® — What is the diameter of cells that can pass through the ISolate® and the diameter of cells that cannot pass through the ISolate®?
The principle of ISolate® is different from the principle of a "sieve" and as such it is not possible to estimate the diameter of the cells that will or will not pass through medium. The performance of ISolate® is more based on movement of the cells, centrifugation speed, and the duration of centrifugation. With the optimum speed and duration, the motile sperm cells will move quicker (thus be at the bottom of the gradient faster) than non motile ones (the same for other cells that are not motile such as white blood cells or cellular fragments). If you centrifuge any sample for a very long time at a higher speed, every cell will eventually go to the bottom. So ISolate® is more like an obstacle that slows some cells, rather than a "sieve" that will keep some cells out depending on their diameter.