State of The Art
Fluorescence microscopy and fluorescence spectroscopy are essential tools in medical and biological sciences. However, in most cases, fluorescent chemical compounds, so-called fluorophores, are used to label the respective structure or molecule. These fluorophore-associated detection methods require a direct binding/interaction of the fluorophore to/with the (bio)molecule of interest, which, conversely, might interfere with the biological structure and/or affect the cellular function of the respective biomolecule. Many chemical fluorophores are also known to be potentially mutagenic and toxic.
In order to circumvent these limitations and to allow substances’ analysis in their native conditions, a new innovative cryogenic system for microscopy and spectroscopy was developed to facilitate label-free fluorescence analytics of (bio)molecules based on their characteristic autofluorescence.
Every (bio)molecule could emit a specific and characteristic autofluorescence signal after being excited to a higher quantum state e.g. by laser energy. However, because of internal quenching effects for most (bio)molecules, there is no autofluorescence signal detectable at room temperature.
In contrast to this, Nanoscopix team has demonstrated that the reduction of sample’s temperature to cryogenic values (up to 10 K / -263°C) significantly increases fluorescence yield by inhibiting especially highly competitive quenching processes. Thus, the innovative cryo-fluorescence setup for microscopy and spectroscopy allows visualisation and chemical characterization of biological samples in a temperature range from 10 K to 350 K. The cryo-microscopy system is characterized by very high sensitivity, and thus, besides autofluorescence detection, standard fluorophores can be applied in significantly reduced concentrations minimizing the risk of toxicity.
In addition the method is characterized by a very high value of potential applications. Beside of microscopic studies of active ingredients in pharmaceutical analysis and analysis of different biomarkers for widespread diseases like diabetes type II, applications in materials science or environmental analysis were possible.