Due to the development of quantum cascade lasers (QCL) in the recent decades it is possible to achieve substantial progress towards reagent-free, molecularly sensitive microscopy.
We -for the first time- developed a QCL based microscope and achieved a reduction of measurement time up to 5 minutes in comparison to hours and days that are needed with comparable common methods like FTIR-Microspectroscopy.
Furthermore the measurement time per area was reduced by 3 orders of magnitude without losing lateral resolution.
In the figure (top) you can see a classical H&E-stained section of mouse jejunum in comparison to an unstained adjacent section of the same tissue [N. Kröger et al., Journal of Biomedical Optics 19 (2014) 111607].
One application for the use of quantum cascade laser-based infrared microscopy is the rapid identification of goblet cells in unstained colon thin sections [N. Kröger-Lui et al., Analyst 2015].
