Orodruin said:
The Nobel Prize in Physics 2018 has been awarded to
Arthur Ashkin (1/2) "for the optical tweezers and their application to biological systems"
Gerard Mourou (1/4) and Donna Strickland (1/4) "for their method of generating high-intensity, ultra-short optical pulses"
Today's Physics prize, especially the prize to Ashkin, highlight inventions that have been important field of biophysics. In graduate school, I worked in the field of single molecule biophysics, which aims to watch the action of single enzymes in order to gain greater knowledge of their mechanisms of action.
This field was primarily built on two different technologies. One (which I used) was the detection of fluorescence from single fluorescent molecules (pioneered, among others, by W.E. Moerner, a co-recipient of the 2014 Nobel Prize in Chemistry), and the other was optical tweezer technology. Optical tweezers give biologists not only the ability to manipulate biological molecules (e.g. to study the mechanical properties of DNA), but also to very sensitively monitor the motion of molecular motors.
In now classic studies in biophysics, researchers were able to watch
DNA polymerase synthesize DNA,
RNA polymerase make RNA from DNA with base pair resolution, and watch the
ribosome move codon-by-codon on an mRNA as it synthesizes protein (the three key steps in the "central dogma" of biology). While Askin was key to developing optical tweezer technology, many biophysicsts (principally, Steven Block at Stanford and Carlos Bustamante at Berkeley) have been at the forefront of applying optical tweezer technology to the study of biological systems (indeed, their work is cited heavily in the Nobel prize material describing the applications of optical tweezers).
In fact, one could make a strong argument that a prize for optical tweezers
and their application to biological systems probably should have been its own prize to Ashkin, Block and Bustamante. While there are still many questions left in the field, these optical tweezer studies have really helped us learn how molecular motor proteins can couple a chemical reaction (such as the hydrolysis of ATP) to the directed motion of protein molecules on their substrates.
Pulsed lasers have also had numerous applications in biophysics, including multiphoton microscopy (most famously, two-photon microscopy). Two photon microscopy is particularly useful for imaging deep into tissue (use of two photon excitation allows with IR lasers that are absorbed and scattered less than visible light by tissue) and has found important applications in neurobiology. Other multiphoton techniques (such as those based on stimulated raman scattering) offer the promise of being able to image specific molecules in living samples without having to label them with an external fluorophore.