Measurement of D-amino acids
D-AAs represent a class of signaling molecules which are largely understudied. The discovery and characterization of D-AAs in living systems necessitates the development, improvement, and application of an assortment of analytical methods. Since D-AAs were initially measured in animals, numerous advances in D-AA analysis have been made– including the development of capillary electrophoresis approaches that are sensitive enough to target subcellular samples, liquid chromatography approaches that simultaneously target many D-AAs, and imaging approaches that can detect these molecules. These approaches, when paired with appropriate experimental design and established animal models, have led to a variety of discoveries (including the characterization of novel enzymes, the establishment of two D-AAs as “classical” transmitters, and a better understanding of many D-AAs in the nervous and endocrine systems).
Best practices for D-AA research, with special emphasis on D-serine, have been recently published with the final aim to move the researchers to greater rigor and reproducibility. See (Mothet et al., Acta Physiol. 2019:e13257).