Talked to Ivan about his experiment with cell adhesion. He uses the AFM to measure the adhesive forces acting between a cell and a surface. The idea is that the cell is bound to the cantilever and bound to the surface that contains specific proteins. The cantilever then pushes and pulls on the cell. The deflection of the cantilever can be translated into force. Today, Ivan was trying to show that there is a consistancy in the cell's adhesive force. The graph shows the force vs. height of the cantilever. The sudden jumps correspond to parts of the cell losing adhesion with the surface, being ripped away. Further studies will be needed to show if the cell is simply seperating from the proteins on the surface or if the surface proteins are being ripped away. This experiment will require the unique setup in this lab, where the surface proteins will be marked with florescent dye. They will only appear if they are on or near the surface, so they will not appear if they are being ripped away from the cell. The unique setup should be able to show if they are being ripped away, and if the time intervals they are being ripped correspond to the sudden jumps in the graph.

One possible use for this would be to create synthetic substances that can change the adhesive forces in cells. Blood clotting, for example, works because of the adhesive forces between specific proteins on the surfaces of the blood cells. Perhaps medication could eventually be manufactured to help individuals who suffer from blood clots.

Project ideas:

While we have been exposed to many projects over this first week, the main theme involves the versatile use of the AMF, and combining the AMF with fluorescence spectroscopy and microscopy. An interesting project might be to build an AFM on a macroscopic scale for use in the classroom. It could be used to teach students the methods used while using an inexpensive macroscopic model. The simplest way to do this would be to build a macroscopic cantilever that deflects laser light, just as in the AFM we are looking at.