The ability to monitor and detect microorganism contamination/infection is important for long space voyages, in order to maintain a clean environment not only for the health of the astronauts, but also for electronics and structural materials. Technologies based upon the polymerase chain reaction (PCR) method have proven to be faster and more sensitive than traditional methods in diagnosis of microorganisms. The real-time PCR technique has been used on the ground to detect microorganisms in the samples collected on the International Space Station (ISS). However, the ability of using PCR to detect infectious agents rapidly and specifically in space is currently unavailable. The major technological blockade to the use of PCR in space is the lack of a hazard-free and microgravity compatible hardware for RNA/DNA isolation.
A RNA/DNA isolation component kit is based on the standard DNA isolation protocol. The kit is a fluidic system with components including syringes and pistons, membranes of different capacities, reagents, valves, and a small pump when necessary. A pre-PCR preparation kit, including the component for DNA elution-DNA/RNA reagent mixture and modified PCR tube, is based on the standard, real-time PCR protocol. The components include syringes and pistons, membranes, reagents, dispenser, and a pre-vacuumed microtube. These kits will be self-enclosed and pipette-free for use in space. They are anticipated to offer similar sensitivities as using the standard protocol in the laboratory on the ground.
The pre-PCR preparation kit includes the component for DNA elution-DNA/PCR reagent mixture (design I), the distributor (design II), and pre-vacuumed real-time PCR tube (design III). The PCR tube has dried primers/probe at the bottom, which is specific for a specific gene of a certain type of microorganism (or using a panel of genes of a certain type of microorganism will be more accurate for diagnosis purpose). The prefilled reagents in the device can be any commercial Tagman, Qiagen, or Bio-Rads standard PCR mastermix. The real-time PCR tube can be used in a modified PCR machine. The features of the real-time PCR system have to be modified to fit the designed PCR tube and the use in space or in the field (design IV).
A 9×10 cm device isolates DNA (design I) or RNA (design II). Multiple devices can be stacked in a holder (design III) that allows processing multiple samples simultaneously. The designed pre-PCR preparation kit, and DNA and RNA isolation devices, are novel. They require only a small amount of sample and processes using a self-enclosed and pipette-free technique. These designs are specific for use in space and other extreme environments where hazardous chemicals have to be confined in an enclosed container, such as military field, polar areas, and in remote areas.
This work was done by Ye Zhang and Honglu Wu of Johnson Space Center.
This invention has been patented by NASA (U.S. Patent Nos. 8,669,096 and 9,017,621). Inquiries concerning nonexclusive or exclusive license for its commercial development should be addressed to
the Patent Counsel, Johnson Space Center, (281) 483-1003.
Refer to MSC-24811-1/3-1.