1. In the now distant year of 1970, the physical nature of the plasma membrane (or any membrane for that matter) was uncertain. Frye and Edidin used Sendai virus to fuse human and mouse cell, then stained the cells with fluorochrome-labeled antibodies specific for human or mouse antigens.1 They watched the unfolding drama in a fluorescent microscope as the human and mouse proteins completely mixed in real time, providing an elegant, direct demonstration of the fluid nature of the plasma membrane and the ability of proteins to freely (more or less) diffuse in the membrane. This was one of the first scientific papers I read as an undergraduate in 1974, and certainly the first I understood. I still look to it as an example of the power of direct observation and the principle that simple experiments can provide profound answers.
2. The power of new techniques, even relatively simple ones, ...
