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A Vertical Comet Assay --
A Vertical Comet Assay --
New Single-Cell Electrophoresis Technology Helps Evaluate DNA Damage to Radiation On Orbit and In Space
New Single-Cell Electrophoresis Technology Helps Evaluate DNA Damage to Radiation On Orbit and In Space
Radiation is bad. At its best, exposure causes sickness while at its worst it undermines the health of DNA, mutating healthy DNA strands into cancerous ones. However, before cells turn rogue, they exhibit signs of change. DNA strands within cells begin to break. The more strand breaks, the likelier the chance of excessive (and permanent) damage.
Radiation is bad. At its best, exposure causes sickness while at its worst it undermines the health of DNA, mutating healthy DNA strands into cancerous ones. However, before cells turn rogue, they exhibit signs of change. DNA strands within cells begin to break. The more strand breaks, the likelier the chance of excessive (and permanent) damage.
Examining the impact of radiation on an individual is often a cumbersome and time-consuming endeavor. Current methods demand a laboratory. However, our team at the University of Alaska Fairbanks are developing portable, time-saving technologies that will allow researchers to measure DNA damage in the field -- for NASA, it means on orbit, in space, and/or in interplanetary trips.
Last updated 5/31/2018
Abstract of Work
Abstract of Work
Space radiation detrimentally affects biological systems and individual organisms. Earth's magnetic field provides protection to terrestrial inhabitants. However, space missions beyond the low Earth orbit pose increased risk to the health of humans because of radiation in space. Both components of space radiation, chronic exposure to low-dose to galactic cosmic rays and random short-term exposures to the energetic particles from the Sun, might increase the risk of malignant transformation.
Damage to the genetic material of cells, its DNA, is considered to be the first and most important step in the malignant transformation of normal cell into a cancerous one. As this concern is addressed in NASA's 2012 roadmap in the domain of Human Health, Life Support and Habitation Systems (HLHS), however, currently we do not have reliable techniques to measure DNA damage on a board of spacecraft. A reliable and sensitive technique to collect data at ground and in flight for radiation risk assessment is in demand.
When exposed to radiation, single and double strand-breaks in cellular DNA are produced. The amount of strand-breaks can, therefore, be correlated to the extent of damage to cells under radiation. One of the most convenient models to study DNA damage and repair process in the live cells is the comet assay, or single cell gel electrophoresis technique. This technique is currently configured to conduct a measurement of live cells under laboratory set-ups.
Therefore, quite often the existing comet assay is not suitable for "in field" applications. Development of a simple and sensitive technique would allow researchers to study crucial cellular processes outside of laboratory boundaries and open possibilities for evaluating many environmental exposures currently unobtainable. DNA damage during short space flight or long-term interplanetary explorations is in particular critical to NASA's missions.
In this project we are aimed at miniaturizing the existing comet assay technique, we call it vertical comet or v-comet, to measure the level of DNA damage in live cells or fix-preserved cellular DNA samples outside the laboratory. This project consists of the following tasks:
develop a microchamber containing live cells or preserved cellular DNA;
use electrophoresis to sample damaged DNA by pulling broken strands into a circulating buffer in a closed-loop;
electrophoresis is continuously applied while the buffer is circulating to accumulate the broken strands;
develop a portable and sensitive fluorescence detector, and
the amount of DNA will be measured by a sensitive fluorescent labeling.
Snapshots of Work
Snapshots of Work
A membrane was placed on an electrode before assembling a miniaturized V-comet device designed, prototyped, and tested by our team at the University of Alaska Fairbanks. Because of the revolutionary technique in V-comet assay, a variety of technical issues constantly arisen during prototyping and testing. We have been frequently brain-storming for possible solutions as prompt as scratched in a bathroom paper towel.
One early V-comet prototype was assembled at the team's laboratory at the University of Alaska Fairbanks.
A functional V-comet device. After assembly, it has a footprint of 1 in by 1 in and is lighter than 2 Oz. For electrophoresis, it currently uses 0.1 V for 90 min for detectable DNA strands. Revision of design and testing protocols are ongoing.
A portable, fully functional fluorescence detector. This device can be battery-driven and equipped with Bluetooth transmission of data to cell phones.
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