| Method |
Optical single transporter recording (OSTR), for optically recording the activity of single transporters in membrane patches. Cells or organelles are firmly attached to isoporous filters, and the transport across membrane patches spanning filter pores is measured by confocal laser scanning microphotolysis (SCAMP) (Wedekind et al., 1994), the amalgamation of microphotolysis and laser scanning microscopy. By application of established theories for the restricted diffusion through small pores, the diffusion channel was approximated as a cylinder with a radius of 4.4-6.1 nm (mean 5.35 nm). |