From 2011.igem.org

Human Practices

A safe screening technique

We propose a light-based transformant screening technique in our project. This technique uses a vector designed by our team, pREX525, wherein the Antibiotic resistance gene is replaced by Green-light absorbing Proteorhodopsin. The stress used for screening is the substrate limitation in minimal media, and the survival advantage is the ability to use light as an energy source.

Antibiotic Resistance gene has been conventionally in use for screening for transformants in cloning. Dependence on antibiotic, which are chemical toxins has the following well established disadvantages.

Horizontal gene transfer of Antibiotic Resistance gene, which can contribute to Drug resistance

Risk of spread of Antibiotic resistance/tolerance among the bacterial flora

Release of Antibiotics, which are essentially toxins, into the environment

Due to these disadvantages, we discourage antibiotic based screening and propose an alternative Light based screening, which is clean and safe. The chemical input for this technique, other than the media itself, is Retinal, which is a safe molecule, and can be bio-synthesized and also degraded endogenously. Using the LED based lighting system which we designed, we can make modifications to existing bioreactors and incubators to adapt to the light-dependent screening in the lab and industrial levels.
We hope that in the near future, synthetic biology is more toxin-free and cleaner, using our light based screening technique.

Spreading the word

To encourage the scientists, engineers and researchers to apply their minds to Synthetic biology, we presented our project at the "Research Expo", an exhibit for innovative projects from around the country, which had an audience of about 60,000 students, young researchers, engineers, biology enthusiasts and senior scientists.