A multi-channel polymerase chain reaction lab-on-a-chip and its application in spaceflight experiment for the study of gene mutation

Astronauts face serious health threats during spaceflight. The two major factors that may lead to an astronauts' physiological dysfunction are space radiation and microgravity. Heavy ion radiation, one of the important components of charged particles in orbit, can cause deoxyribonucleic acid (DNA) damage and gene mutations. Microgravity can also affect a series of cell physiology functions, including cytoskeleton remodeling, DNA modification, interactions between molecules, etc. Several ionizing radiation experiments performed in our previous study suggested the variation in the mutation across different selected immune genes. Here, we performed a further experiment (IGM-BIT-1) on board the International Space Station (ISS) to explore the molecule evolution rules of the selected DNA. To conduct the on-orbit amplification of the DNA fragments from the antibody encoding genes in the ISS, a self-developed portable and programmable PCR device was designed and produced. We developed a novel PCR chip that consists of a multi-channel optical adhesive reaction chamber and a miniature thermal cycler. The reaction chamber was cost effective and disposable. The thermal cycler was used to achieve both rapid heating and cooling. As the DNA amplification yield of IGM-BIT-1 PCR device was much similar or even higher than the commercial devices, the IGM-BIT-1 payload has been proven to be suitable for space life science research.