Hello everyone,
I want to do a chemotaxis migration assay with PBMCs. I have gone through the literature to find the optimum pore size of the transwell membrane but got confused. Some people have used 8 µm pore size while some others have used 5 µm pore size. Could somebody help me in this regard if working on a similar aspect?
Hello Preeti Rathi
Transwell pore size should be chosen based on cell type and size. Generally, the selected membrane pore size should be smaller than the cell diameter when in suspension. You may perform a pilot experiment to determine the appropriate membrane pore size, which allows sufficient cell migration toward a chemoattractant while minimizing random cell migration without chemoattractant.
Generally, most leukocyte cell lines have a diameter of 10–15μm and will require a 5 or 8μm pore diameter. However, smaller cell types, such as primary lymphocytes, range between 7μm and 10μm in diameter and so may require a smaller pore size of 3μm to prevent high levels of cell migration in the absence of chemoattractant. Other cell types like fibroblast cells (for instance, NIH3T3) or cancer cells (for example, MDA-MAB 231) would require 5μm pore size.
So, I would suggest for PBMCs use a smaller pore size of 3μm since the average mean cell diameters range between 7μm - 10μm.
Best.
