While working in the lab, you isolate a cell from a mouse and a cell from a human and fuse them together to form a live, hybrid cell. You then use an antibody that recognizes all mouse membrane proteins and is labeled with a green fluorophore, and another antibody that recognizes all human membrane proteins and is labeled with a red fluorophore to visualize the location of membrane proteins on the hybrid cell. Immediately after fusion of the cells, hybrids incubated with both antibodies appear to have one distinct half that is all green, while the other half is all red.  

A) What do you expect to see if you look again an hour later and what does this demonstrate about the cell membrane?  

B)  You now wish to compare the properties of the mouse and human membrane proteins in the hybrid cells. Describe a technique that could be used to study the behaviour of the proteins in the cell membrane.  

C)  You accidentally leave your cells next to the air conditioner where cold air blows on them for the hour you were eating lunch.  How have your cells' membranes changed to maintain fluidity?