Question: how are you able to watch DNA move with gold and glowing things?

Alice Rhind-Tutt answered on 11 Feb 2021:

I attach the gold particles to the dna – a bit like tying marble along a piece of string. Then I x-ray the dna/gold mixture and the gold shows up really clearly on x-rays (unlike DNA which is too small and not dense enough). X-rays move at the speed of light so it’s a bit like taking lots of photos of the gold and seeing how it moves, therefore seeing how the DNA moves. I do the same experiment with glowing things known as fluorophores – these are particles that emit light so instead of x-rays I use a microscope that can detect the light coming off them.