Time-resolved low-dose microscopy of glutamine synthetase molecules.

Time sequences of low-exposure images from the enzyme molecules of glutamine synthetase have been recorded digitally using an on-line recording system. Processing the images results in a time sequence of averaged molecule images, which, in the very beginning, exhibit the molecule structure still undamaged by electron irradiation. Different sources of the noise which obscures structural details, such as shot noise, stain embedding and radiation damage, are investigated.