Carbotrace 680 is our red optotracer for labeling repetitive motifs in proteins and carbohydrates. Generally, Carbotrace labeling is strongest with protein aggregates. Homoglucans like cellulose are labeled reliably, albeit with lower quantum yield. Heteroglucans with low degree of branching like starches are labeled and can be distingiushed by their spectral fingerpint. Generally labelling of hemicelluloses is weak or absent. Specifically, Carbotrace 680 has been used to image cellulose and starch components in plant cells and differentiate between those components using multi-laser/multi-detector analysis with confocal microscopy. Using a fluorescence spectrophotometer to acquire excitation and emission spectra, a unique spectral signature allows to differentiate between α(1-3), α(1-4), α(1-6), β(1-3), β(1-4) and β(1-6) linked glucans. As such, Carbotrace 680 labels cell wall components such as Cellulose, Chitin, Laminarin and the hemicellulose xyloglucan. Further, Carbotrace 680 has been used to determine relative carbohydrate content and elasticity of cell walls in plant material.
