Updated: May 28, 2020
STARMUS 2016 featured many talks about the cosmos and using sophisticated instruments, like LIGOS, to peer backward in time. Just as fascinating was a talk by Eric Betzig, whose quest is to image the very small—that is, living cells.
A challenge for biologists is to see 3D images inside live cells and at the resolution of a molecule. There are many obstacles to this type of imaging, including something called the diffraction limit which restricts how close two things can be and still be imaged sharply. Another problem is that the amount of light needed to see small things results in phototoxicity—damage to the cells. Although it can be useful to look at dead cells, real insights will come from looking inside living cells and observing how they operate.
Dr. Betzig found ways to get around the imaging obstacles. First with photo activated localization microscopy (PALM) and later with Lattice Light Sheet Microcopy and Structured Illumination Microscopy (SIM).
Brightly illuminating a cell causes the substructures to reflect light back such that the light from one substructure interferes with the one next to it. To get around this, Dr. Betzig found that he could build up an image by using a random process to illuminate small parts of the cell. If you do this enough times, you’ll eventually illuminate each part. No more interference. The image is sharp. This is essentially the PALM approach.
His later approaches use more sophisticated techniques to illuminate cells and minimize the instantaneous power directed at a cell. This allows him to image living cells in stunning detail. He showed a movie of a lysosome in action inside a cell. Quite amazing.
Dr. Betzig won the nobel prize in 2014 for his early work. At STARMUS 2016 he said this was not his best work—as he feels his best is yet to come. I can’t wait to see what else he does!
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