Using Optical Tweezers Combined with Total Internal Reflection Microscopy to Study Interactions Between the ER and...

Optical tweezers have been used to trap and micromanipulate several biological specimens ranging from DNA, macromolecules, organelles to single celled organisms. Using a combination of the refraction and scattering of laser light from a focused laser beam, refractile objects are physically captured and can be moved within the surrounding media. The technique is routinely used to determine biophysical properties such as the forces exerted by motor proteins. Here, we describe how optical tweezers combined with total internal reflection fluorescence (TIRF) microscopy can be used to assess physical interactions between organelles, more specifically the ER and Golgi bodies in plant cells.