Monitoring lactate with a fluorescent sensor

Abstract

When organisms break down glucose in low-oxygen environments, the end product is lactate. Most ways to measure this metabolite—to monitor athletic performance or diagnose diseases, for example—depend on enzymes. Now, researchers report a DNA aptamer that can bind l -lactate at physiological levels ( Angew. Chem., Int. Ed. 2023, DOI: 10.1002/anie.202212879 ). Detection based on DNA aptamers , short sequences with a stem-loop structure that can bind other molecules, tends to be more temperature stable and reversible than enzymatic methods. A team led by Juewen Liu of the University of Waterloo used in vitro selection to develop an aptamer that binds to l -lactate when magnesium is present. According to Liu, the Mg 2+ ions may form a bridge between the negatively charged DNA and small, negatively charged lactate molecules. By adding a fluorophore and an antisense strand with a fluorescence quencher, the researchers turned the aptamer into a fluorescent