Download Full Text (108 KB)

Faculty Advisors

Sandlers, Yana; Kondratov, Roman


An extraction procedure and gas chromatography mass spectrometry (GC-MS) method was developed for quantitation of plasma amino acids. The experimental workflow included extraction of amino acids from plasma, followed by derivatization protocol for GC-MS compatibility. Automated Mass spectral Deconvolution and Identification System (AMDIS) and laboratory developed library was used for compound identification. Levels of plasma amino acids were calculated based on one point calibration with non-physiological amino acid L-norvaline as internal standard. The assay was applied to obtain and monitor levels of plasma amino acids to study the effect of feeding restriction on the circadian clock in mice. The circadian clock is an evolutionarily conserved molecular machinery that consist of transcription-translation feedback loops, which oscillate throughout the day and produce rhythms that dictate the behavior and physiology of all living organisms. At the center of the circadian clock are CLOCK and BMAL1 that regulate various metabolic processes such as mTOR signaling and coordinate them with daily rhythms. Results of our current study show that the amino acids oscillate during the day but do not correlate with the feeding paradigm. Due to presence of multiple peaks, it can be concluded that the oscillations are not circadian in nature, which suggests probable complex regulation of amino acids.

Publication Date



College of Sciences and Health Professions


Life Sciences | Medicine and Health Sciences | Physical Sciences and Mathematics

Development of a GC-MS Method for Investigation Mouse Plasma Amino Acid Levels and their Significance to the Circadian Clock