Growing specialized cell types in an environment that resembles the in vivo state as closely as possible is becoming more important in basic science, clinical and translational research. As a result, cell and tissue culture techniques now encompass the use of permeable supports with microporous membranes that provide researchers improved ability in culturing polarized cells. Cells are then not only grown in a more natural state, but are also able to further differentiate allowing more information to be acquired regarding higher and more complex cellular functioning. I have used many microporous supports that are available on the market and find the Corning Costar supports to be the most effective and convenient to use.
When I first began culturing cells on microporous membrane supports I opted for the cheapest supports I could buy, but quickly found that inconvenience outweighed the cost efficiency. Many of the cheaper supports are sold separately from the plates that you will put them in during cell culturing. I found this to be an unnecessary hassle because not all of the membrane inserts fit nicely into all plate types and aspirating media and/or treating cells can be more difficult than necessary. Therefore, I recommend spending the extra money on packs of plates that already contain the inserts of your choice. These plates will contain microporous membrane supports that fit perfectly into the wells and allow enough space for media changes and cell treatments both above and below the membrane. As a result, it will be much easier to study effects of specific treatments on apical and basolateral sides of a polarized cell.
I have found that the Costar supports are most convenient to use if you plan to view the cells under the microscope while they are still on the membrane after treatment or post-migration. Unlike several other brands, the supports provided by Costar are transparent, are stable enough to withstand several post-treatment protocols including many staining procedures, and allow you to clearly visualize your cells of interest pre- or post-staining under a microscope. Additionally, the Costar supports are available pre-treated with a matrix that will allow many cell types to attach, but can also be treated with your matrix or molecule of interest before cell attachment. These microporous membranes can be easily coated with additional protein or matrix molecules by pipetting enough of the protein or matrix containing liquid on one or both sides of the membrane, allowing it to incubate for 1 h at room temperature, and then washing off the excess with tissue culture suitable 1X PBS.
So far, I have used the Costar supports for wound healing and migration assays, to polarize cells for further differentiation, and for apical versus basolateral cell treatments. Each time I performed a new assay I found it fairly easy to determine what size and type of microporous membrane I needed to use for each assay and cell type by utilizing the Permeable Support Application Chart provided on Costar’s website. However, I did find that cells that are normally difficult to culture may be finicky on these microporous membranes. As a result, I often needed to use a smaller than recommended pore size, which immediately fixed the problem. Overall, I have been more than satisfied with the quality and diversity of use of the Costar Transwell Suports and recommend them for purchase by anyone studying cellular functions using a variety of assays including those that require convenient and independent access to apical and basolateral plasma membrane domains.
Amy Bellmeyer, M.S.
Research Technician
Northwestern University
Division of Pulmonary and Critical Care Medicine