BIO 310 Lecture Notes - Lecture 4: Green Fluorescent Protein, Cell Membrane, Photobleaching
Document Summary
Proteins will diffuse throughout the entire plasma membrane. Within 40 minutes after fusion, they will disperse. Fluorescence recovery after photobleaching (frap) measures the rate of lateral diffusion of a membrane protein. Usually on proteins that express green fluorescent protein (gfp) Shine laser onto a certain part of the cell to bleach fluorescent signal from the area no fluorescence in that area. Measure how long it takes to recover. Happens very quickly because fluorescent proteins from adjacent regions will move to that region shows that proteins are very mobile. However, firmly anchored proteins will take a long time to recover since the proteins are not free to diffuse to the bleached site. Fluorescence loss in photobleaching (flip) is the opposite of frap. Continuous bleaching any molecule that moves into the region where the laser is shining. The measurement region is near the bleached area.
