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.

Human spaceflight endeavors present an opportunity to expand our presence beyond Earth. To this end, it is crucial to understand and diagnose effects of long‐term space travel on the human body. Developing tools for targeted, on‐site detection of specific DNA sequences will allow us to establish research and diagnostics platforms that will benefit space programs. We describe a simple DNA diagnostic method that utilizes colorimetric loop‐mediated isothermal amplification (LAMP) to enable detection of a repetitive telomeric DNA sequence in as little as 30 minutes. A proof of concept assay for this method was carried out using existing hardware on the International Space Station and the results were read instantly by an astronaut through a simple color change of the reaction mixture. LAMP offers a novel platform for on‐orbit DNA‐based diagnostics that can be deployed on the International Space Station and to the broader benefit of space programs.

The distance and duration of human spaceflight missions is set to markedly increase over the coming decade as we prepare to send astronauts to Mars. However, the health impact of long-term exposure to cosmic radiation and microgravity is not fully understood. In order to identify the molecular mechanisms underpinning the effects of space travel on human health, we must develop the capacity to monitor changes in gene expression and DNA integrity in space. Here, we report successful implementation of three molecular biology procedures on board the International Space Station (ISS) using a miniaturized thermal cycler system and C. elegans as a model organism: first, DNA extraction–the initial step for any type of DNA analysis; second, reverse transcription of RNA to generate complementary DNA (cDNA); and third, the subsequent semi-quantitative PCR amplification of cDNA to analyze gene expression changes in space. These molecular procedures represent a significant expansion of the budding molecular biology capabilities of the ISS and will permit more complex analyses of space-induced genetic changes during spaceflight missions aboard the ISS and beyond.

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As we explore beyond Earth, astronauts may be at risk for harmful DNA damage caused by ionizing radiation. Double-strand breaks are a type of DNA damage that can be repaired by two major cellular pathways: non-homologous end joining, during which insertions or deletions may be added at the break site, and homologous recombination, in which the DNA sequence often remains unchanged. Previous work suggests that space conditions may impact the choice of DNA repair pathway, potentially compounding the risks of increased radiation exposure during space travel. However, our understanding of this problem has been limited by technical and safety concerns, which have prevented integral study of the DNA repair process in space. The CRISPR/Cas9 gene editing system offers a model for the safe and targeted generation of double-strand breaks in eukaryotes. Here we describe a CRISPR-based assay for DNA break induction and assessment of double-strand break repair pathway choice entirely in space. As necessary steps in this process, we describe the first successful genetic transformation and CRISPR/Cas9 genome editing in space. These milestones represent a significant expansion of the molecular biology toolkit onboard the International Space Station.