Biological samples contain labile molecules that deteriorate rapidly ex-vivo. Terrestrially, biological samples are preserved either by freezing them (–80 °C) or by including preservation chemicals. While chemical preservation may be ideal for certain molecules, their functionality is selective and can, while preserving one set of molecules, damage others. Refrigeration poses major logistical challenges of power and logistics. These two options pose major cost and logistics burdens to NASA as they continue to collect biological specimens during flight. Although the International Space Station (ISS) includes a refrigerator to preserve samples, there are no such capabilities aboard return vehicles, especially unmanned vehicles. Furthermore, it should be noted that payloads that are dropped off in remote locations often are recovered after many days, making the biological samples extremely vulnerable to ambient conditions, often rendering them useless.
Although fluid samples are routinely collected from astronauts immediately upon their return to Earth, the process of re-entry causes stresses on astronauts’ physiology that could potentially cause incorrect inferences to be made regarding the effects of microgravity. Ideally, fluid samples would be collected and analyzed during missions; however, due to the lack of appropriate analysis equipment onboard current delivery vessels and habitats, there is a strong need for the ability to store fluids for analysis at a later time.
A fluid preservation system (FPS) was developed to address NASA’s need for a method to preserve body samples (primarily blood and urine) under ambient conditions that are collected from astronauts during flight. The FPS is based on collecting and storing samples with automatic separation of supernatant fluid without the use of refrigeration or chemicals, and is ideally suited for the environment and capabilities aboard the ISS. Sample processing can be performed within the FPS container and hermetically sealed in a small, convenient package.
The general procedure of the FPS tube involves using the FPS as a blood collection device and plasma preparation system that reduces the number of processing steps. Reducing processing steps not only minimizes the effort for a user (astronaut), but more importantly, significantly reduces the possibility of contamination and therefore ensures highly sterile and stable plasma containment for high-quality, long-term storage. The process uses the evacuated FPS tube to siphon blood from the patient into the tube.
Once full, the tube is centrifuged at 2,000 g for 15 minutes, and plasma is separated into a different compartment of the FPS tube than the red blood cells, white blood cells, and platelets. This plasma is then sealed and stored onboard the ISS, and can be sent to Earth for further analysis. Samples in the FPS units can be stored under ambient conditions and are designed to withstand conditions associated with Earth re-entry.
This work was done by Naresh Menon, Greg Bearman, Cheryl Tan, and Julian Down of ChromoLogic LLC for Johnson Space Center.
In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:
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