Student: Stephanie Hice, Graduate Student in Food Science and Technology, Iowa State University
Faculty Advisor: Byron Brehm-Stecher
Polymerase Chain Reaction (PCR) is widely considered the “gold standard” for DNA amplification and detection of bacterial pathogens. However, most PCR instruments are inherently complex and cumbersome, limiting their utility in the field here on Earth, let alone aboard the International Space Station.
The miniPCR machine is a portable alternative to its somewhat unwieldly predecessors, and is currently being used to identify unknown biological samples aboard the ISS. However, despite a shortened processing time of 25 minutes, the system still requires post-amplification gel electrophoresis, adding time and supplementary equipment to the process. Additional savings in time-to-result, launch weight and non-reliance on ancillary equipment are possible.
Isothermal methods of amplifying nucleic acids, such as Recombinase Polymerase Amplification (RPA), can be used as a PCR alternative. Our laboratory is developing fast and portable RPA assays that provide in-tube colorimetric or fluorescent detection of pathogen-specific DNA. Presently, this work is intended to benefit food processors, enabling rapid, in-plant testing of foods and environments. However, the benefits of our approach to the problem of microbial contamination on Earth may also be directly applicable to the issue of pathogens in space.
Availability of a low weight, non-cycling and single-tube alternative to the miniPCR system could facilitate routine screening for bacterial pathogens aboard the ISS, or amplify DNA from unknown microbes in support of in-space sequencing efforts.