Up and Down for Chemical Visibility
Jena scientists extend mass spectrometric imaging to non-flat biological surfaces.
Laser-Ablation-Electrospray-Ionisation (LAESI), a mass spectrometric imaging technology, can now be used to visualise the distribution of chemical substances not only on flat tissue sections, but additionally on almost non-altered biological samples with three dimensional shapes like warped, hairy, or coarse surfaces.
A distance sensor was implemented to measure the height profile of a sample before the actual mass spectrometric analysis. The recorded height profile is used to correct for the distance between the focusing lens and the sample surface. Benjamin Bartels is first author of the study and PhD student of Professor Hans Peter Saluz from the Leibniz Institute of Natural Product Research and Infection Biology – Hans Knöll Institute (HKI). Professor Saluz is a designated expert for technology development with long lasting imaging experience at the interface between biology, physics and chemistry. The source of the laser-based technique was custom-built in the group of Dr. Aleš Svatoš in the Max Planck Institute for Chemical Ecology (MPI-CE). Dr. Norbert Danz from the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF) designed a specific lens system for the implemented infrared lasers.
With the improved laboratory setup scientists can now investigate a larger variety of biological samples, for example insect exoskeletons or microbial colonies within their natural environment, but also different trichomes of a plant leaf. In this way not only the presence of a chemical substance can be identified, but also its potential local enrichment or gradients. The identified molecules are often secondary metabolites produced by, for example, microorganisms or plants, used for the communication with symbionts or competitors. The improved technology opens up entirely new perspectives to answer, for example, ecological questions with the aim to control and rebalance disturbed ecosystems. [SG]
Bartels B, Kulkarni P, Danz N, Böcker S, Saluz HP, Svatoš A (2017) Mapping metabolites from rough terrain: laser ablation electrospray ionization on non-flat samples. RSC Advances 7, 9045-9050, DOI: 10.1039/C6RA26854D http://dx.doi.org/10.1039/C6RA26854D