Development of microchip electrophoresis methods and instrumentation for chiral amino acid analysis on future spaceflight missions

Abstract

We summarize the status of microfluidic instrumentation for future missions of spaceflight exploration seeking signs of life on extraterrestrial destinations. Recent results from the Microfluidic Life Analyzer (MILA) effort at the NASA Jet Propulsion Lab. will be presented, including new methodol. for the chiral discrimination of amino acid enantiomers as biosignatures. A status report on the technol. readiness of the portable Chem. Laptop instrument, which utilizes microchip electrophoresis coupled to laser induced fluorescence detection, as well as reports on initial testing outside of the lab. environment, will also be provided. By the use of multiple sepn. conditions involving mixts. of aq./nonaq. solvents, surfactants, and cyclodextrins, we are able to baseline resolve all enantiomers of FITC-labeled alanine, serine, leucine, glutamic acid, and aspartic acid. Temp. was also explored as a means for optimized chiral sepns. In order to aid with visualization of the efficiency of sepns. for more complex mixts., an algorithm was created which calcd. resoln. for all possible amino acid combinations in matrix form, and represented resoln. for each combination on a color scale ranging from green (resoln. greater than one) and red (zero resoln.). Finally, the Chem. Laptop portable system was tested for amino acid sepns. in the field environment. In these tests, the JPL developed unit was operated entirely under battery power and used to perform microchip electrophoresis sepns. coupled to laser induced fluorescence detection, with at least 500pM limit of detection sensitivity for labeled amino acids.