Cell migration is a highly integrated, multistep process that plays an important role in the progression of various diseases including cancer, atherosclerosis, arthritis, and mental retardation. To study cell migration in vitro, most researchers have traditionally used a popular tool known as the Boyden Chamber. However, the Boyden Chamber is no longer the only option as a newer, innovative assay format has been developed, sometimes called a 2D Gap Closure Assay. Both formats have their place, and depending on your research goals one format may be more suitable than the other.
A Boyden Chamber consists of a cell culture insert nested in the well of a cell culture plate. The insert contains a polycarbonate membrane at the bottom with a defined pore size. This pore size is dependent on the cell type being studied. The polycarbonate membrane serves as a barrier to discriminate migratory cells from non-migratory cells. Cells are seeded in the top of the insert in serum-free media, while serum or a similar chemoattractant is placed in the well below. Migratory cells are able to extend protrusions towards the chemoattractant (via actin cytoskeleton reorganization), ultimately passing through the pores of the polycarbonate membrane and clinging to the bottom side of the membrane. Non-migratory cells stay in the upper chamber. After the non-migratory cells are removed from the top of the membrane, the migratory cells can be stained and quantified. Boyden chamber assays are ideal to study migration via a chemoattractant gradient. However, the Boyden Chamber assay format can only be used for quantitative and endpoint analysis.
The Gap Closure Assay consists of a cell culture plate containing some kind of barrier that separates the adherent cells from a defined area, or “gap”, where cells do not attach. After cells are seeded, this barrier is removed to expose a cell-free region which is now available for cells to migrate through and begin to close the gap. 2D Migration Gap Closure Assays are more versatile than Boyden Chamber Assays as they allow for qualitative or quantitative analysis in both real-time and at endpoint. Also, there is no need to worry about choosing a membrane pore size; assay kits are universal and can accommodate any cell type. Overall sensitivity is better than the Boyden Chamber Assay Format, and adaptability to automation can be achieved. However, Gap Closure Assays do not support a chemoattractant gradient.
Cell Biolabs, Inc. is currently the only company to manufacture a wide variety of Cell Migration Assays in both Boyden Chamber and Gap Closure assay formats. For more information on the advantages of each assay format, click here.