Assessing Antibody Microarrays for Space Missions: Effect of Long-Term Storage, Gamma Radiation, and Temperature Shifts on Printed and Fluorescently Labeled Antibodies

Abstract

Antibody microarrays are becoming frequently used tools for analytical purposes. A key factor for optimal performance is the stability of the immobilized (capturing) antibodies as well as those that have been fluorescently labeled to achieve the immunological test (tracers). This is especially critical for long-distance transport, field testing, or planetary exploration. A number of different environmental stresses may affect the antibody integrity, such as dryness, sudden temperature shift cycles, or, as in the case of space science, exposure to large quantities of the highly penetrating gamma radiation. Here, we report on the effect of certain stabilizing solutions for long-term storage of printed antibody microarrays under different conditions. We tested the effect of gamma radiation on printed and freeze- or vacuum-dried fluorescent antibodies at working concentrations (tracer antibodies), as well as the effect of multiple cycles of sudden and prolonged temperature shifts on the stability of fluorescently labeled tracer antibody cocktails. Our results show that (i) antibody microarrays are stable at room temperature when printed on stabilizing spotting solutions for at least 6 months, (ii) lyophilized and vacuum-dried fluorescently labeled tracer antibodies are stable for more than 9 months of sudden temperature shift cycles (-20°C to 25°C and 50°C), and (iii) both printed and freeze- or vacuum-dried fluorescent tracer antibodies are stable after several-fold excess of the dose of gamma radiation expected during a mission to Mars. Although different antibodies may exhibit different susceptibilities, we conclude that, in general, antibodies are suitable for use in planetary exploration purposes if they are properly treated and stored with the use of stabilizing substances.

Detecting Nonvolatile Life- and Nonlife-Derived Organics in a Carbonaceous Chondrite Analogue with a New Multiplex Immunoassay and Its Relevance for Planetary Exploration

“…Important mission constraints have been addressed in all cases, such as the resistance of antibodies or other reagents to space conditions during the mission, planetary protection issues, contamination controls, and potential false positive results and how to manage them. Along with other authors, we have reported that antibodies and other biochemical materials have the capability to resist certain conditions with regard to space and other high stress environments such as high vacuum, thermal cycling (de Diego-Castilla et al , 2011 ), and ionizing radiation (Thompson et al , 2006 ; Baqué et al , 2011 ; de Diego-Castilla et al , 2011 ; Derveni et al , 2012 ; Carr et al , 2013 ), and it is estimated that such biochemical materials would remain viable over the course of, for example, a 2-year mission to Mars.…”

Feasibility of Detecting Bioorganic Compounds in Enceladus Plumes with the Enceladus Organic Analyzer

“…In addition, EOA can perform spiking experiments of known standards to reduce ambiguity of identification, since each analysis requires in total only a few microliters of labeled sample solution. While the radiation resistance of the Pacific Blue and Cascade Blue fluorescent probes and of the buffers used by EOA has not yet been explicitly determined, similar fluorescent probes, including fluorescein, SYBR Green, and Alexa Fluor 633, all show more than sufficient stability for a mission profile like that of the EOA (Thompson et al , 2006 ; Le Postollec et al , 2009 ; de Diego-Castilla et al , 2011 ; Carr et al , 2013 ). Furthermore, the dyes and buffers are stored dry, cold, and in an inert atmosphere on-chip to minimize chemical degradation.…”

Irradiation effects on antibody performance in the frame of biochip-based instruments development for space exploration

“…Among the next tools to search for signs of past or present life in our Solar System, several instruments based on the biochip technology have been proposed in the framework of planetary exploration. A biochip is a miniaturized device composed of molecular recognition tools (or affinity receptors) like antibodies (Baqué et al 2011b; de Diego-Castilla et al 2011;Parro et al 2005Parro et al , 2011aSims et al 2005Sims et al , 2012 or aptamers (Baqué et al 2011a), which allows the detection of hundreds of different compounds in a single assay. Widely developed for biotechnology use and medical or environmental diagnostics (see for example Wang 2006), miniaturized instruments based on biochips have been indeed proposed and studied for biosignature detection in an astrobiological context since more than 15 years (McKay et al 2000;Parro et al 2005;Le Postollec et al 2007;Sims et al 2005).…”