In a research paper published in Cellulose, our structure-responsive optotracer molecule Carbotrace 680 was used to demonstrate the potential of optotracing for carbohydrate anatomical mapping and spectral imaging. As an example - to show the utility and ease of the new technology - Carbotrace 680 was applied to thinly sliced potato samples and then imaged with a fluorescence microscope. Strikingly, Carbotrace 680 bound to cellulose in the cell wall exhibited a unique fluorescent spectrum which was easily separated from the fluorescent spectrum of the molecule when bound to amylose and amylopectin in the potato's starch granules.
Image: The acquired image elegantly shows cell walls in great detail labeled yellow and starch granules labeled green. Evidently, the image made an impression with the editors of the "Cellulose" journal, since it was selected to appear on the cover of the 26(7) edition.
Testing a variety of glucans (polysaccharides made up of glucose) with different types of glycosidic linkages by acquiring the optical spectrum of Carbotrace 680 when bound to the carbohydrate, it was found that Carbotrace 680 differentiates α(1-3), α(1-4), α(1-6), β(1-3), β(1-4) and β(1-6) linked glucans at the molecular level and allows differentiation of cellulose and laminarin from amylose, amylopectin, glycogen and dextran. As starch is an important carrier material for drug formulations, the structure-responsive optotracer Carbotrace 680 was further applied for analyzing heat-induced swelling of starch granules and was proposed as a tool for quality control of starch-containing materials by monitoring its structural changes during production and packaging. The study describes the use of optotracing for anatomical mapping of plant tissue as well as spectral imaging and shows the potential for Carbotrace as an important tool in packaging and production of foods and drugs and in biorefinery applications for renewable materials and biofuels.