Co-Culture results

I'm very excited to share my results from my co-culturing experiment! Dr. Keese and I came across some very interesting results, especially in the to 50% MDCK/50%BSC-I mixtures. This is the first time anyone has performed a co-culturing experiment using ECIS, so Dr. Keese was just as excited as I was to see the outcomes of this experiment. We expected to see these two different types of cells to integrate with one another, attaching to the surface of the electrode in an evenly mixed layer. However, we found that these cells joined together in like-groups, looking like islands under the microscope. With this conclusion, it would not be logical to perform a wound healing assay on our next co-culturing experiment as we had originally planned. A wound-healing assay would kill off any cells on the electrode, and therefore would kill one type of cell- whichever island had attached to the electrode. 

With this new insight into how different cell types interact with one another, we need to redesign the next steps in our ongoing co-culturing experiment. 

First, it is critical to take a deeper look into how these islands are formed, and why. To do this, I filled 16 wells of a cell plate with varying concentrations of MDCK and BSC-I cells. I filled two wells with pure MDCK, two with pure BSC-I, and 12 with a 50/50 mixture of both cell types (1ml of solution per well). This cell plate does not contain any electrodes, it is purely for the purposes of examining the growth of cells under the microscope. Dr. Keese will be staining the cells incrementally to see how they attach to the surface, and at what rate they will form like-groups. I will be working with different cell types in the future to see if all cells form like-groups when grown together in the same environment.  I'm looking forward to posting pictures of these stained cells in next Friday's blog post!

Finally, Dr. Keese and I analyzed our results in ECIS. Although the number of MDCK cells seemed to have been was lower than the BSC1 cells (a possible source of error), we still had nicely mixed cell population data. Our results are best demonstrated in a frequency scan. Here is the frequency scan displaying the results from every well: 

And here is the frequency scan that I have manipulated to display the average of all pure MDCK wells, pure BSC-I, .5/.5 mixture, and cell-free solution (medium):

As you can see from these two frequency scans, MDCK cells show up better at lower frequencies, and then switch places with BSC-I cells at around 20 hours. At about this time, the .5/.5 mixture is seen as having a higher resistance than both the MDCK and BSC-I cells. What frequency tells us about our data: At higher frequencies, impedance is more affected by extent of cell-coverage, whereas at lower frequencies, we  are better able to see the changes in the spaces between or underneath the cells.  

A few weeks ago, Dr. Keese gave me a presentation on how ECIS works, and spoke about cell migration. I remember that in one slide of his presentation, there was a video of cells, and how they grew in response to a wound healing assay. I asked him if using this type of time-lapse video would be beneficial to seeing how our two types of cells are interacting with one other. We will have to wait and see what his answer is next week! Here is an example of the time-lapse documentation of cell migration I am referencing: