Individual blood cells flying through capillaries can now be viewed in real time. The technique, called stimulated raman scattering (SRS) microscopy, generates videos of moving cells deep inside tissue and could replace biopsies in the diagnosis of cancers.
The technique works by shining laser beams at the sample, which causes atoms within the molecules to vibrate. Different molecules vibrate at characteristic frequencies and therefore interact with the beams in different ways. Software built into the microscope can pick up these differences. This means cells can be imaged without using dyes, which can be toxic or interfere with biological processes.
Until now, however, SRS was only accurate enough for use on dead tissue samples, because too much light was scattered back from the tissue. That made it difficult to capture an image through thicker samples, such as a human arm. The imaging process was also too slow to use on moving, living organisms.
The technique works by shining laser beams at the sample, which causes atoms within the molecules to vibrate. Different molecules vibrate at characteristic frequencies and therefore interact with the beams in different ways. Software built into the microscope can pick up these differences. This means cells can be imaged without using dyes, which can be toxic or interfere with biological processes.
Until now, however, SRS was only accurate enough for use on dead tissue samples, because too much light was scattered back from the tissue. That made it difficult to capture an image through thicker samples, such as a human arm. The imaging process was also too slow to use on moving, living organisms.
