Glucose is the main source of energy for organisms, and it is important to understand the spatiotemporal dynamics of intracellular glucose. Single fluorescent protein-based glucose indicators, named “Red Glifons” have been developed that apply to live-cell and dual-color imaging. These indicators exhibited more than 3-fold increase in fluorescence intensity in the presence of 10 mM glucose. The two Red Glifons developed have different half-maximal effective concentration (EC₅₀) values for glucose (300 μM and 3,000 μM) and are able to monitor a wide range of glucose dynamics. Red Glifon combined with green indicators allowing visualization of the interplay between glucose and ATP, lactate, or pyruvate. Glucose influx in the pharyngeal muscle of Caenorhabditis elegans, enteroendocrine cells, and human iPS cell-derived cardiac myocytes was observed using the Red Glifons. Thus these red glucose indicators serve as a multi-color imaging toolkit for investigating complex interactions in energy metabolism.

葡萄糖是生物体的主要能量来源，了解细胞内葡萄糖的时空动态非常重要。已开发出用于活细胞和双色成像的单一荧光蛋白葡萄糖指示剂，名为“Red Glifons”。在存在 10 mM 葡萄糖的情况下，这些指标的荧光强度增加了 3 倍以上。开发的两种 Red Glifons 对葡萄糖（300 μM 和 3,000 μM）具有不同的半最大有效浓度 (EC ₅₀ ) 值，并且能够监测广泛的葡萄糖动力学。Red Glifon 与绿色指示器相结合，可以可视化葡萄糖和 ATP、乳酸或丙酮酸之间的相互作用。秀丽隐杆线虫咽肌中的葡萄糖流入、肠内分泌细胞和人 iPS 细胞衍生的心肌细胞使用 Red Glifons 进行了观察。因此，这些红色葡萄糖指示剂可作为多色成像工具包，用于研究能量代谢中的复杂相互作用。