Results for “space biosensors”

NASA NTRS1996

Medical and surgical applications of space biosensor technology

Researchers in space life sciences are rapidly approaching a technology impasse. Many of the critical questions on the impact of spaceflight on living systems simply cannot be answered with the limited available technologies. Research subjects, particularly small animal models like the rat, must be allowed to function relatively untended and unrestrained for long periods to fully reflect the impact of microgravity and spaceflight on their behavior and physiology. These requirements preclude the use of present hard-wired instrumentation techniques and limited data acquisition systems. Implantable sensors and miniaturized biotelemetry are the only means of capturing the fundamental and critical data. This same biosensor and biotelemetry technology has direct application to Earth-based medicine and surgery. Continuous, on-line data acquisition and improved measurement capabilities combined with the ease and flexibility offered by automated, wireless, and portable instruments and data systems, should provide a boon to the health care industry. Playing a key role in this technology revolution is the Sensors 2000! (S2K!) Program at NASA Ames Research Center. S2K!, in collaboration with space life sciences researchers and managers, provides an integrated capability for sensor technology development and applications, including advanced biosensor technology development, spaceflight hardware development, and technology transfer and commercialization. S2K! is presently collaborating on several spaceflight projects with dual-use medical applications. One prime example is a collaboration with the Fetal Treatment Center (FTC) at the University of California at San Francisco. The goal is to develop and apply implantable chemical sensor and biotelemetry technology to continuously monitor fetal patients during extra-uterine surgery, replacement into the womb, through birth and beyond. Once validated for ground use, the method will be transitioned to spaceflight applications to remotely monitor key biochemical parameters in flight animals. Successful application of NASA implantable biosensor and biotelemetry technologies should accelerate the advancement of this and other modern medical procedures while furthering the exploration of life in space.

NASA Discipline General Space Life Sciences↗

NASA NTRS2017

Identification of Novel Desiccation-Tolerant S. cerevisiae Strains for Deep Space Biosensors

NASA's BioSentinel mission, a secondary payload that will fly on the Space Launch System's first Exploration Mission (EM-1), utilizes the budding yeast S. cerevisiae to study the biological response to the deep space radiation environment. Yeast samples are desiccated prior to launch to suspend growth and metabolism while the spacecraft travels to its target heliocentric orbit beyond Low Earth Orbit. Each sample is then rehydrated at the desired time points to reactivate the cells. A major risk in this mission is the loss of cell viability that occurs in the recovery period following the desiccation and rehydration process. Cell survival is essential for the detection of the biological response to features in the deep space environment, including ionizing radiation. The aim of this study is to mitigate viable cell loss in future biosensors by identifying mutations and genes that confer tolerance to desiccation stress in rad51, a radiation-sensitive yeast strain. We initiated a screen for desiccation-tolerance after rehydrating cells that were desiccated for three years, and selected various clones exhibiting robust growth. To verify retention of radiation sensitivity in the isolated clones - a crucial feature for a successful biosensor - we exposed them to ionizing radiation. Finally, to elucidate the genetic and molecular bases for observed desiccation-tolerance, we will perform whole-genome sequencing of those rad51 clones that exhibit both robust growth and radiation sensitivity following desiccation. The identification and characterization of desiccation-tolerant strains will allow us to engineer a biological model that will be resilient in face of the challenges of the deep space environment, and will thus ensure the experimental success of future biosensor missions.

S. cerevisiae↗

NASA NTRS2017

Identification of Novel Desiccation-Tolerant S. cerevisiae Strains for Deep Space Biosensors

NASA's BioSentinel mission, a secondary payload that will fly on the Space Launch Systems first Exploration Mission (EM-1), utilizes the budding yeast S. cerevisiae to study the biological response to the deep space radiation environment. Yeast samples are desiccated prior to launch to suspend growth and metabolism while the spacecraft travels to its target heliocentric orbit beyond Low Earth Orbit. Each sample is then rehydrated at the desired time points to reactivate the cells. A major risk in this mission is the loss of cell viability that occurs in the recovery period following the desiccation and rehydration process. Cell survival is essential for the detection of the biological response to features in the deep space environment, including ionizing radiation.The aim of this study is to mitigate viable cell loss in future biosensors by identifying mutations and genes that confer tolerance to desiccation stress in rad51, a radiation-sensitive yeast strain. We initiated a screen for desiccation-tolerance after rehydrating cells that were desiccated for three years, and selected various clones exhibiting robust growth. To verify retention of radiation sensitivity in the isolated clonesa crucial feature for a successful biosensorwe exposed them to ionizing radiation. Finally, to elucidate the genetic and molecular bases for observed desiccation-tolerance, we will perform whole-genome sequencing of those rad51 clones that exhibit both robust growth and radiation sensitivity following desiccation. The identification and characterization of desiccation-tolerant strains will allow us to engineer a biological model that will be resilient in face of the challenges of the deep space environment, and will thus ensure the experimental success of future biosensor missions.

S. cerevisiae↗

NASA NTRS1997

Space Biosensor Systems: Implications for Technology Transfer

To meet the need for continuous, automated monitoring of animal subjects, including; humans, during space flight, NASA is developing advanced physiologic sensor and biotelemetry system technologies. The ability to continuously track basic physiological parameters, such as heart rate, blood pH, and body temperature, in untethered subjects in space is a challenging task. At NASA's Ames Research Center, where a key focus is gravitational biology research, engineers have teamed with life scientists to develop wireless sensor systems for automated physiologic monitoring of animal models as small as the rat. This technology is also being adapted, in collaboration with medical professionals, to meet human clinical monitoring needs both in space and on the ground. Thus, these advanced monitoring technologies have important dual-use functions; they meet space flight data collection requirements and constraints, while concurrently addressing a number of monitoring and data acquisition challenges on the ground in areas of clinical monitoring and biomedical research. Additional applications for these and related technologies are being sought and additional partnerships established that enhance development efforts, reduce costs and facilitate technology infusion between the public and private sectors. This paper describes technology transfer and co-development projects that have evolved out of NASA's miniaturized, implantable chemical sensor development efforts.

Hines, J. W.↗

NASA NTRS2014

Biosentinel: Developing a Space Radiation Biosensor

Ionizing radiation presents a major challenge to human exploration and long-term residence in space. The deep-space radiation spectrum includes highly energetic particles that generate double strand breaks (DSBs), deleterious DNA lesions that are usually repaired without errors via homologous recombination (HR), a conserved pathway in all eukaryotes. While progress identifying and characterizing biological radiation effects using Earth-based facilities has been significant, no terrestrial source duplicates the unique space radiation environment.We are developing a biosensor-based nanosatellite to fly aboard NASAs Space Launch System Exploration Mission 1, expected to launch in 2017 and reach a 1AU (astronomic unit) heliocentric orbit. Our biosensor (called BioSentinel) uses the yeast S. cerevisiae to measure DSBs in response to ambient space radiation. The BioSentinel strain contains engineered genetic defects that prevent growth until and unless a radiation-induced DSB near a reporter gene activates the yeasts HR repair mechanisms. Thus, culture growth and metabolic activity directly indicate a successful DSB-and-repair event. In parallel, HR-defective and wild type strains will provide survival data. Desiccated cells will be carried within independent culture microwells, built into 96-well microfluidic cards. Each microwell set will be activated by media addition at different time points over 18 months, and cell growth will be tracked continuously via optical density. One reserve set will be activated only in the occurrence of a solar particle event. Biological measurements will be compared to data provided by onboard physical dosimeters and to Earth-based experiments.BioSentinel will conduct the first study of biological response to space radiation outside Low Earth Orbit in over 40 years. BioSentinel will thus address strategic knowledge gaps related to the biological effects of space radiation and will provide an adaptable platform to perform human-relevant measurements in multiple space environments. We hope that it can therefore be used on the ISS, on and around other planetary bodies as well as other exploration platforms as a self-contained system that will allow us to compare and calibrate different radiation environments.BioSentinels results will be critical for improving interpretation of the effects of space radiation exposure, and for reducing the risk associated with long-term human exploration.

space radiation↗

NASA NTRS2015

BioSentinel: Developing a Space Radiation Biosensor

BioSentinel is an autonomous fully self-contained science mission that will conduct the first study of the biological response to space radiation outside low Earth orbit (LEO) in over 40 years. The 4-unit (4U) BioSentinel biosensor system, is housed within a 6-Unit (6U) spacecraft, and uses yeast cells in multiple independent microfluidic cards to detect and measure DNA damage that occurs in response to ambient space radiation. Cell growth and metabolic activity will be measured using a 3-color LED detection system and a metabolic indicator dye with a dedicated thermal control system per fluidic card.

Radiation biosensor↗

NASA NTRS2001

Carbon Nanotube Biosensors for Space Molecule Detection and Clinical Molecular Diagnostics

Both space molecule detection and clinical molecule diagnostics need to develop ultra sensitive biosensors for detection of less than attomole molecules such as amino acids for DNA. However all the electrode sensor systems including those fabricated from the existing carbon nanotubes, have a background level of nA (nanoAmp). This has limited DNA or other molecule detection to nA level or molecules whose concentration is, much higher than attomole level. A program has been created by NASA and NCI (National Cancer Institute) to exploit the possibility of carbon nanotube based biosensors to solve this problem for both's interest. In this talk, I will present our effort on the evaluation and novel design of carbon nanotubes as electrode biosensors with strategies to minimize background currents while maximizing signal intensity.The fabrication of nanotube electrode arrays, immobilization of molecular probes on nanotube electrodes and in vitro biosensor testing will also be discussed.

Han, Jie↗

NASA NTRS2014

BioSentinel/Mars: Interplanetary Space Radiation Biosensor Experiment in Martian Transit on Mars 2020

Despite significant progress understanding biological radiation effects via terrestrial studies, no terrestrial source duplicates space’s unique radiation environment. Furthermore, no biological experiments have been conducted beyond low Earth orbit since Apollo. Understanding space’s fundamental biological effects requires overcoming these limitations. The BioSentinel 4U payload, under development for flight aboard Exploration Mission-1, measures biological responses to deep space radiation. Traveling to more than 1AU from Earth, BioSentinel/EM-1 will record DNA double-strand breaks (DSBs) repaired using a pathway common to humans and BioSentinel’s bioengineered yeast model organism, responding to as few as one biologically repaired DSB. The BioSentinel/Mars 4U instrument (6-8kg; 5-8W; 0.2-1MB/week) would include eighteen 16-well biosensor fluidic cards, activated biweekly during Mars 2020’s cruise phase, to provide a dose-dependent rate of DSB/repair. The instrument, which includes solid-state sensors for total ionizing dose and linear-energy-transfer spectra, addresses MEPAG SKG-B3 by simultaneously measuring both spectra and biological effects of space radiation. Biological measurements are rendered reliable by independent replicate experiments. The spatio-temporal uniformity of interplanetary galactic cosmic radiation makes BioSentinel/EM1 and BioSentinel/Mars approximate replicates, except for any major differences in solar particle events. Results will be compared to Earth and ISS controls to characterize the radiation/reduced-gravity parameter space by its biological impact.

BioSentinel↗

NASA NTRSDate not supplied

Engineered Yeast to Test Risks for Human Exploration of the Lunar Surface

Jessica W. Chau, Natalie N. Ball, Aditya Hindupur, Sandra T. Vu, Jennifer Gil Acevedo, Lauren C. Liddell, Chinmayee Govinda Raj, Gentry, Sergio R. Santa Maria, A. Mark Settles Crewed exploration of the Moon carries risks of long duration exposure to reduced gravity and to deep space radiation. The Lunar Explorer Instrument for space biology Applications (LEIA) investigates the effects of increased radiation and reduced gravity on yeast viability and growth in a Commercial Lunar Payload Services (CLPS) surface mission to the south polar region. LEIA conducts yeast genetics experiments to quantify growth, metabolism, and synthetic biology-enabled production of human nutrients, while taking real time measurements of biologically relevant radiation exposure on the lunar surface. We have engineered beta-carotene producing yeast strains to test the importance of selected DNA damage repair and reactive oxygen species (ROS) defense pathways in mitigating cellular damage from lunar surface radiation. Carotenoids are important dietary antioxidants, and beta-carotene is pro-vitamin A, which is needed for vision and immune function. Carotenoids are sensitive to ROS produced by ionizing radiation and NASA is testing on-demand production of carotenoids from yeast in the BioNutrients space flight experiments. In LEIA, we test the effects of deep space on carotenoid yield in engineered yeast strains. The LEIA team uses CRISPR-Cas9 to engineer yeast to express carotenoids as well as to generate loss-of-function mutations. We are generating mutations in the RAD51 DNA damage repair locus and three genes that function to reduce oxidative damage to the cell: SOD1, SOD2, and TSA1. These strains are tested for carotenoid production using microfluidics and LED spectroscopy to allow remote sensing of cellular growth and carotenoid levels. Keywords: synthetic biology, oxidative stress tolerance, biosensors, space radiation, beyond low Earth orbit, lunar surface, CRISPR/Cas9, gene editing, desiccation, carotenoids.

synthetic biology↗

NASA NTRS2021

Space Biology Research and Biosensor Technologies: Past, Present, and Future

In light of future missions beyond low Earth orbit (LEO) and the potential establishment of bases on the Moon and Mars, the effects of the deep space environment on biology need to be examined in order to develop protective countermeasures. Although many biological experiments have been performed in space since the 1960s, most have occurred in LEO and for only short periods of time. These LEO missions have studied many biological phenomena in a variety of model organisms, and have utilized a broad range of technologies. However, given the constraints of the deep space environment, upcoming deep space biological missions will be largely limited to microbial organisms and plant seeds using miniaturized technologies. Small satellites such as CubeSats are capable of querying relevant space environments using novel, miniaturized instruments and biosensors. CubeSats also provide a low-cost alternative to larger, more complex missions, and require minimal crew support, if any. Several have been deployed in LEO, but the next iterations of biological CubeSats will travel beyond LEO. They will utilize biosensors that can better elucidate the effects of the space environment on biology, allowing humanity to return safely to deep space, venturing farther than ever before.

space biology↗

NASA NTRSDate not supplied

Evaluating the sensitivity of BioSentinel yeast biosensors to deep space relevant radiation

Explore the source record for details and available documents.

Rachel Gilbert↗

NASA NTRS2017

Biosentinel: Improving Desiccation Tolerance of Yeast Biosensors for Deep-Space Missions

BioSentinel is one of 13 secondary payloads to be deployed on Exploration Mission 1 (EM-1) in 2019. We will use the budding yeast Saccharomyces cerevisiae as a biosensor to determine how deep-space radiation affects living organisms and to potentially quantify radiation levels through radiation damage analysis. Radiation can damage DNA through double strand breaks (DSBs), which can normally be repaired by homologous recombination. Two yeast strains will be air-dried and stored in microfluidic cards within the payload: a wild-type control strain and a radiation sensitive rad51 mutant that is deficient in DSB repairs. Throughout the mission, the microfluidic cards will be rehydrated with growth medium and an indicator dye. Growth rates of each strain will be measured through LED detection of the reduction of the indicator dye, which correlates with DNA repair and the amount of radiation damage accumulated. Results from BioSentinel will be compared to analog experiments on the ISS and on Earth. It is well known that desiccation can damage yeast cells and decrease viability over time. We performed a screen for desiccation-tolerant rad51 strains. We selected 20 re-isolates of rad51 and ran a weekly screen for desiccation-tolerant mutants for five weeks. Our data shows that viability decreases over time, confirming previous research findings. Isolates L2, L5 and L14 indicate desiccation tolerance and are candidates for whole-genome sequencing. More time is needed to determine whether a specific strain is truly desiccation tolerant. Furthermore, we conducted an intracellular trehalose assay to test how intracellular trehalose concentrations affect or protect the mutant strains against desiccation stress. S. cerevisiae cell and reagent concentrations from a previously established intracellular trehalose protocol did not yield significant absorbance measurements, so we tested varying cell and reagent concentrations and determined proper concentrations for successful protocol use.

BioSentinel↗

NASA NTRSDate not supplied

NASA's Biosentinel Mission: Lessons Learned and What's Next

In the last two years, two BioSentinel payloads were launched to space. The ISS mission launched in December 2021, and returned to the ground in August 2022 after successfully completing eight biological experiments while validating the different instruments. On the other hand, the deep space mission launched onboard Artemis I in November 2022, and is currently in a heliocentric orbit over 20 million kilometers away from the Earth. Even though all hardware subsystems were validated in deep space, the microfluidic subsystems experienced anomalies throughout the initial 6-month mission. The main goals of this presentation are (1) to present flight data from the deep space payload, including biology, fluidics, electronics, data processing, and mission operations, and (2) to discuss the lessons learned – what worked and what did not – from this unique complex mission, and how these lessons are aiding in the development of the Lunar Exploration Instrument for space biology Applications (LEIA) mission, launching to the lunar surface on a commercial lander in 2026. As of the writing of this abstract, the satellite continues to work nominally, communicating to Earth via the Deep Space Network (DSN) twice per week. Importantly, the mission received and extension to continue recording data on the deep space radiation environment on its way to solar maximum (i.e., higher probability of solar particle events). BioSentinel is supported by NASA Exploration Systems Development Mission Directorate (ESDMD).

BioSentinel↗

NASA NTRS2016

BioSentinel: Biosensors for Deep-Space Radiation Study

The BioSentinel mission will be deployed on NASA's Exploration Mission 1 (EM-1) in 2018. We will use the budding yeast, Saccharomyces cerevisiae, as a biosensor to study the effect of deep-space radiation on living cells. The BioSentinel mission will be the first investigation of a biological response to space radiation outside Low Earth Orbit (LEO) in over 40 years. Radiation can cause damage such as double stand breaks (DSBs) on DNA. The yeast cell was chosen for this mission because it is genetically controllable, shares homology with human cells in its DNA repair pathways, and can be stored in a desiccated state for long durations. Three yeast strains will be stored dry in multiple microfluidic cards: a wild type control strain, a mutant defective strain that cannot repair DSBs, and a biosensor strain that can only grow if it gets DSB-and-repair events occurring near a specific gene. Growth and metabolic activity of each strain will be measured by a 3-color LED optical detection system. Parallel experiments will be done on the International Space Station and on Earth so that we can compare the results to that of deep space. One of our main objectives is to characterize the microfluidic card activation sequence before the mission. To increase the sensitivity of yeast cells as biosensors, desiccated yeast in each card will be resuspended in a rehydration buffer. After several weeks, the rehydration buffer will be exchanged with a growth medium in order to measure yeast growth and metabolic activity. We are currently working on a time-course experiment to better understand the effects of the rehydration buffer on the response to ionizing radiation. We will resuspend the dried yeast in our rehydration medium over a period of time; then each week, we will measure the viability and ionizing radiation sensitivity of different yeast strains taken from this rehydration buffer. The data obtained in this study will be useful in finalizing the card activation sequence for this mission.

Yeast↗

NASA NTRS2017

Biosentinel: Improving Desiccation Tolerance of Yeast Biosensors for Deep-Space Missions

BioSentinel is one of 13 secondary payloads to be deployed on Exploration Mission 1 (EM-1) in 2019. We will use the budding yeast Saccharomyces cerevisiae as a biosensor to determine how deep-space radiation affects living organisms and to potentially quantify radiation levels through radiation damage analysis. Radiation can damage DNA through double strand breaks (DSBs), which can normally be repaired by homologous recombination. Two yeast strains will be air-dried and stored in microfluidic cards within the payload: a wild-type control strain and a radiation sensitive rad51 mutant that is deficient in DSB repairs. Throughout the mission, the microfluidic cards will be rehydrated with growth medium and an indicator dye. Growth rates of each strain will be measured through LED detection of the reduction of the indicator dye, which correlates with DNA repair and the amount of radiation damage accumulated. Results from BioSentinel will be compared to analog experiments on the ISS and on Earth. It is well known that desiccation can damage yeast cells and decrease viability over time. We performed a screen for desiccation-tolerant rad51 strains. We selected 20 re-isolates of rad51 and ran a weekly screen for desiccation-tolerant mutants for five weeks. Our data shows that viability decreases over time, confirming previous research findings. Isolates L2, L5 and L14 indicate desiccation tolerance and are candidates for whole-genome sequencing. More time is needed to determine whether a specific strain is truly desiccation tolerant. Furthermore, we conducted an intracellular trehalose assay to test how intracellular trehalose concentrations affect or protect the mutant strains against desiccation stress. S. cerevisiae cell and reagent concentrations from a previously established intracellular trehalose protocol did not yield significant absorbance measurements, so we tested varying cell and reagent concentrations and determined proper concentrations for successful protocol use.

BioSentinel↗

NASA NTRS2017

Biosensor Integration Development ExMC/Canadian Space Agency Collaboration

In support of the NASA Human Research Program Exploration Medical Capability (ExMC) Element, NASA Ames Research Center (ARC) established a collaborative effort with the Canadian Space Agency (CSA). The collaboration focuses on leveraging CSA capability in the areas of biosensors and decision support that will augment future development of such components for Exploration Missions. The CSA advancement of biosensors enables NASA to focus on the integration and data management associated with these types of components through the system currently under development by the Medical Data Architecture (MDA) project. This approach has enabled the establishment of a successful collaborative working relationship between ExMC and CSA.Applying lessons learned from the fiscal year 2016 (FY16) Human Exploration Research Analog (HERA) campaign, CSA and NASA ARC developed a solution to provide real-time feedback to researchers who monitor the collection of vital signs data from a wearable Astroskin garment. The advances in the interfaces included the development of an iPad application (by CSA) to wirelessly forward the vital signs data to the MDA system, which collected the vital signs data through a receiver developed by NASA ARC. The development of these interfaces aims to provide communications between the Astroskin and the MDA system such that data may be seamlessly collected, stored and retrieved by the MDA. The first steps towards this goal were demonstrated in FY16. In FY17, ExMC will complete the first in a series of test beds that establishes a system to automate collection and management of vital sign data from the Astroskin, and other sources of data, to provide information for a crewmember to make medical decisions. In addition, the MDA Test Bed 1 will enable CSA to evaluate and optimize biosensor advancement and facilitate decision support algorithm development.

Vital signs↗

NASA NTRS2017

Biosensor Integration Development ExMC/Canadian Space Agency Collaboration

In support of the NASA Human Research Program Exploration Medical Capability (ExMC) Element, NASA Ames Research Center (ARC) established a collaborative effort with the Canadian Space Agency (CSA). The collaboration focuses on leveraging CSA capability in the areas of biosensors and decision support that will augment future development of such components for Exploration Missions. The CSA advancement of biosensors enables NASA to focus on the integration and data management associated with these types of components through the system currently under development by the Medical Data Architecture (MDA) project. This approach has enabled the establishment of a successful collaborative working relationship between ExMC and CSA.Applying lessons learned from the fiscal year 2016 (FY16) Human Exploration Research Analog (HERA) campaign, CSA and NASA ARC developed a solution to provide real-time feedback to researchers who monitor the collection of vital signs data from a wearable Astroskin garment. The advances in the interfaces included the development of an iPad application (by CSA) to wirelessly forward the vital signs data to the MDA system, which collected the vital signs data through a receiver developed by NASA ARC. The development of these interfaces aims to provide communications between the Astroskin and the MDA system such that data may be seamlessly collected, stored and retrieved by the MDA. The first steps towards this goal were demonstrated in FY16. In FY17, ExMC will complete the first in a series of test beds that establishes a system to automate collection and management of vital sign data from the Astroskin, and other sources of data, to provide information for a crewmember to make medical decisions. In addition, the MDA Test Bed 1 will enable CSA to evaluate and optimize biosensor advancement and facilitate decision support algorithm development.

Astroskin↗

NASA NTRS2016

Genomic and Phenotypic Characterization of Yeast Biosensor for Deep-space Radiation

The BioSentinel mission was selected to launch as a secondary payload onboard NASA Exploration Mission 1 (EM-1) in 2018. In BioSentinel, the budding yeast Saccharomyces cerevisiae will be used as a biosensor to measure the long-term impact of deep-space radiation to living organisms. In the 4U-payload, desiccated yeast cells from different strains will be stored inside microfluidic cards equipped with 3-color LED optical detection system to monitor cell growth and metabolic activity. At different times throughout the 12-month mission, these cards will be filled with liquid yeast growth media to rehydrate and grow the desiccated cells. The growth and metabolic rates of wild-type and radiation-sensitive strains in deep-space radiation environment will be compared to the rates measured in the ground- and microgravity-control units. These rates will also be correlated with measurements obtained from onboard physical dosimeters. In our preliminary long-term desiccation study, we found that air-drying yeast cells in 10% trehalose is the best method of cell preservation in order to survive the entire 18-month mission duration (6-month pre-launch plus 12-month full-mission periods). However, our study also revealed that desiccated yeast cells have decreasing viability over time when stored in payload-like environment. This suggests that the yeast biosensor will have different population of cells at different time points during the long-term mission. In this study, we are characterizing genomic and phenotypic changes in our yeast biosensor due to long-term storage and desiccation. For each yeast strain that will be part of the biosensor, several clones were reisolated after long-term storage by desiccation. These clones were compared to their respective original isolate in terms of genomic composition, desiccation tolerance and radiation sensitivity. Interestingly, clones from a radiation-sensitive mutant have better desiccation tolerance compared to their original isolate without losing radiation sensitivity. We employed Next-Generation Sequencing technology to better understand this phenotypic variation. Current effort is focusing on the analysis of high-throughput sequencing data to look for genomic changes in these reisolated clones compared to their original isolate.

yeast↗