Successful amplification of DNA aboard the International Space Station

Abstract

As the range and duration of human ventures into space increase, it becomes imperative that we understand the effects of the cosmic environment on astronaut health. Molecular technologies now widely used in research and medicine will need to become available in space to ensure appropriate care of astronauts. The polymerase chain reaction (PCR) is the gold standard for DNA analysis, yet its potential for use on-orbit remains under-explored. We describe DNA amplification aboard the International Space Station (ISS) through the use of a miniaturized miniPCR system. Target sequences in plasmid, zebrafish genomic DNA, and bisulfite-treated DNA were successfully amplified under a variety of conditions. Methylation-specific primers differentially amplified bisulfite-treated samples as would be expected under standard laboratory conditions. Our findings establish proof of concept for targeted detection of DNA sequences during spaceflight and lay a foundation for future uses ranging from environmental monitoring to on-orbit diagnostics.

Nucleic acid detection aboard the International Space Station by colorimetric loop‐mediated isothermal amplification (LAMP)

“…The PCR and LAMP reactions were launched aboard SS John Glenn OA‐7 on April 18th, 2017. The miniPCR thermal cycler used during the Genes in Space‐1 mission was also used for both Genes in Space‐2 experiments . For the PCR experiment, astronauts Jack D. Fischer and Peggy Whitson programmed the miniPCR instrument with temperatures and times for amplification that had been optimized on ground.…”

“…The absence of PCR product in space samples using Q5 could have several explanations, such as reduced enzyme activity due to prolonged storage or post‐amplification DNA degradation between the time of PCR and subsequent gel electrophoresis several weeks later resulting from the enzyme's 3′‐5′ exonuclease activity. Given that previous ISS experiments involving a mutant of Q5 were successful, it is unlikely that these results represent differences in enzyme activity between space and ground.…”

“…The miniPCR thermal cycler used during the Genes in Space-1 mission was also used for both Genes in Space-2 experiments. 19 For the PCR experiment, astronauts Jack D. Fischer and Peggy Whitson programmed the miniPCR instrument with temperatures and times for amplification that had been optimized on ground. After amplification, the PCR products were returned to ground, where the contents of each tube were analyzed by gel electrophoresis.…”

“…18 A series of DNA analysis technologies such as the polymerase chain reaction (PCR), quantitative PCR and DNA sequencing have already been demonstrated on the ISS. [19][20][21] These molecular biology | 161 RUBINFIEN Et al. technologies have contributed immensely to our understanding of the biological responses to microgravity in general. While all these efforts have been successful, they require specialized equipment and extensive molecular biology expertise to prepare, execute, and analyze the results.…”

Updating PCR

“…In 2016, the first successful PCR experiment was conducted onboard the International Space Station [4]. But what enables us to do this?…”