In our laboratory, all the normal safety precautions were taken for the course of our wetlab work. Normal protocols were observed for plasmid constructions, DNA amplification, digestions, and any outlined assays. These protocols accounted for any necessary safety procedures that would be expected in the course of work. However, outside these normal procedures, our procedure called for the bacterial production of hydrogen sulfide, which can be toxic in large quantities. To account for this acute production from bacterial colonies, our team took some additional safety precautions.
Safety Accounting for Production of Hydrogen Sulfide
We realize that hydrogen sulfide (H2S) is dangerous and flammable. We will have the MSDS posted at all times. To ensure that bacteria do not constitutively produce H2S, we will have our plasmid under control of an inducible promoter. H2S production will be 'turned on' only in ventilated hoods. Goggles and gloves will be worn at all times when handling our bacteria. Fortunately, H2S has a rotten egg smell at 0.5 ppm (50% of people can detect it at 0.00047 ppm) that is easily detectable by smell. The safe exposure limit of H2S is 8 ppm over two months.
To address the safety questions posed by iGEM:
- Based on our experimental design, our project can be categorized as fairly low-risk. With highly experienced graduate and faculty advisors guiding us, the probability of significant safety issues or random error was largely diminished. In addition, our iGEM project did not involve working with any infectious host organisms or chemicals, besides those documented above (H2S). We also carefully engineered our systems, so that if one or several bioparts changed their function or stop working as intended, then consequences would be minimized. Thus, with low hazard and low probability, our project overall had low safety risks.
- Our BioBrick submissions do not pose any sort of significant safety issues.
- Yale University has its own institutional review board, and our project underwent rigorous scrutinization from a range of faculty members in the Molecular Biochemistry and Biophysics Department. We received approval from all overseeing groups.
- In terms of general safety issues, our team believes that the best case practice is comprehensive documentation. With more detailed and better characterized parts, synthetic biology can be an extremely controlled and safe experience, even for young undergraduate researchers!