Yanling Chen Author Answered Oct 17, 2012
The Scripps Research Institute
1. Please make sure that the bottom of the insert, when immersed in medium, has no small bubbles trapped underneath (especially the middle area). The microporous membrane should be soaked evenly in medium.
2. Please add the volumes of media/cell according to manufacturer's manual, which keeps the inside/outside media at certain levels.
3. Avoid swirling medium when adding cells to the insert.
4. The transwell plate should be kept steady when incubated, reduce moving it around or shaking it.
5. For your experiments, you may also way to try different cell seeding densities, and/or a shorter migration time.
Hope these can help.