[BAO01-P14] Investigation of optimum density of fluorescent dyes used for Life Detection Microscope on Mars surface
Keywords:Mars, fluorescent microscope
The Curiosity: Mars Science Laboratory (MSL) of NASA detected organic matter in the Gale Crater on Mars2). H2O ice was discovered in Phoenix mission3). The seasonal apparence of black lines on the slope of craters called Recurrent Slope Lineae (RSL) were obseved by Mars Reconnaissance Orbiter (MRO)4), which may be related some water activities. These suggest the possible presence of life on Mars.
Yamagishi and his colleagues have proposed a Mars exploration mission for in situ life detection by directly observing cells and organic matters in the soil on the surface of Mars with a fluorescence microscope5). The microscope was named as Life Detection Microscope (LDM). The LDM has the sensitivity 1000 times higher than that by Viking apparatus. We plan to use two fluorescent dyes, SYTO24 and Propidium Iodide (PI), in LDM. SYTO24 can be transported across the cell membrane and stains organic matter locating both outside and inside of cells. PI can not be transported across the cell membrane nor can stain in side of cells. By using these two dyes, it is possible to judge the presence or absence of organic matter and whether the latter be the living or dead cells.
We have dettermined the optimum concentrations of PI and SYTO 24 for LDM and report our progress on the development of LDM.
1) Navarro-Ginzalez, R., et al.,2006, PNAS, 103: 16089-16094. 2) Freissient, C., et al.,2015, J. Geophys. Res. Planets. 120: 495-514. 3) Feldoman, W.C., et al., 2002. Science, 297, 75-78. 4) Alfred S. McEwen, et al., 2011, Science, 333: 740-743. 5) Yamagishi, A., et al., 2010, Bio. Sci. Space. 24: 67-82