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Cornell iGEM

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Dry Lab

CT Scan

To get a closer look at the internal structure of our hollow fiber reactor and to monitor the durability of the fibers after heavy filtration we got a Computed Tomography (CT) scan of the reactor with the help of Cornell's Biotechnology Resource Center Imaging Center. We are very concerned with how the fiber material holds up to use as we don't want the filter to be compromised and for our cells to escape into the environment. This technique could be used to determine the life-span and suggested replacement times of such systems.

Material Design

The box has been tested to last for over 5 months in our project for 2012. Since it is meant to be used outside in the field, the box must be durable and water proof in order to filter the polluted water and safeguard the electronics from the environment. The box is also self-sustaining in a sense that a solar panel is used to provide electricity for the electronics and that it can endure the environment as it may be placed by a river to sequester some of the heavy metals from the river.

Flow Rate Testing

In order to determine our requirements for the pump, we tested the flow rate through a setup with the prefilter and fiber reactor. Since the fiber reactor membranes are extremely delicate, we had to make sure our pump could overcome the system’s high resistance without causing any leaks. Initially, this was quite difficult, since we had to prime the system with water for the pump to work at all. The prefilter does not outlet any water until it is completely full. We were able to solve this by connecting the inlet to a separate water source and using hydrostatic head to carefully fill each component. We then matched the fiber reactor’s maximum pressure rating to the pump’s outlet pressure based on the current from the power supply.

Luria Broth Testing

If LB remains in the fiber reactor for too long, foreign matter may start to grow and contaminate the filter. To prevent this from happening, a test was conducted to see how long it took for LB to flow out of the fiber reactor. Solutions of LB and tonic water of varying concentrations were run through the fiber reactor, and the amount of solution that came out of the filter, as well as the concentration of solution, were measured. This was done by using tonic water, which fluoresces under UV light because it contains quinine. Overall, it was determined that the amount of LB remaining in the fiber reactor after inoculation is negligible and will not lead to contamination.