In the whole competition, safety always comes first. So we make efforts to protect ourselves and the environment
from any potential harm in the project. All efforts we do for safety can be summed up into two aspects: Safe
Project Design and Safe Lab Work.
Safe Project Design
In our project, we are trying to build a group visible and low-cost bio-sensors of heavy metal, which can detect
heavy metal ions in aqueous solution. We standardize the lysis gene SRRz and the β-galactosidase gene as
a reporter, and link some specific inducible promoters of heavy metal ions to this reporter. Then we transform
these devices into E.coli BL21 to construct engineering bacteria that can rapidly detect heavy metal ions
in aqueous solution. To ensure the safety of our project, we take following measures.
1. Non-pathogenic Chassis
We choose E.coli BL21i as our genetically modified chassis organism in our project. Our chassis bacteria have
not acquired any characteristics that would enable them to compromise human immune system/other systems or
evade detection and destruction by the former or facilitate spread between people/animals, which makes them
harmless from both a personal and public health point of view.
2. Harmless Parts
Our parts are all safe for human. We ensure that none of the genes or parts that we were assembling would act
as virulence factors according to current professional knowledge, and that no known pathogens would be involved
in our research. It is thus conclusive that none of the parts would raise any safety issues.
3. Safe Gene Circuits
We use a series of specific inducible promoters of heavy metal ions, which guarantees that our bacteria won’t
produce large amounts of protein without being induced. And as we use lysis gene SRRz as the reporter, once
the promoters are induced, the cells’ wall will be lysed and the cells will die.
4. Proof-of-concept Experiment
The original intention of the project is to develop a group visible and low-cost bio-sensors to detect heavy
metal ions in the environment. In order to prove the usefulness of this concept, we did a series of experiments.
At first, we use simulated pollution scenes which were constructed by dissolving heavy metal ions either
in TBS buffer or in environmental water samples from the lake on campus and the factory manufacturing metallic
materials. Moreover, we took water samples from the factory to test the function of our engineered bacteria.
Among all experiments, we always follow the Do Not Release requirements.
Safe Lab Work
Before we start our experiments, our PI and instructors have given us lessons about safety of lab work, teaching
us the rules and regulations of biological experiments systematically. And members in our team have read
the established laboratory safety principles of our school. From that, we have learned a complete understanding
of experimental risks associated with synthetic biology.
The topics in our safety training can be summarized as followings:
1. Biological safety
The strains are restricted to the lab so that the cells are continuously under rigorous control without any possibility
to contact the outside environment. Therefore, we have prevented recombinant DNA from flowing out into the
environment. Additionally, the bacterial hosts are laboratory strains which are likely to be highly uncompetitive
compared wild bacteria in the outside environment.
2. Chemical Safety
Inevitably, we are exposed to toxic chemical reagents, such as GelRed, DEPC and so on. To reduce such risks,
some measures are taken when operating toxic chemical reagents. We place the toxic chemical reagents in the
specific safety cabinets, and relevant operations are all done in the specific fume cupboards. We also set
a special area for the preparation of agarose gel and agarose gel electrophoresis. Double pairs of gloves
are required to wear while working in this area.
3. Safety of Electric and Instruments
Before starting our lab work, the electrical engineer of the lab showed us the circuit layout and told us details
about the use of these equipment. When finish our tasks every day, we need to take turns to check these electric
appliances. Before using every kind of equipment, we read the instructions a few times to avoid any safety
problems. And we will cut off the power when do not use them. Particularly for using centrifugal machines,
we will make sure that we have already balanced it and covered the lid well before centrifugation.
4. Transport of Materials
Our organisms and DNA were kept securely in the school and Imperial College laboratories and transfer of any
biological materials was performed under strictly controlled conditions as per the regulations - double sealed
containers to prevent against a leak to the surrounding environment, clearly labelled and protected. Containers
were clearly labelled with the details of the two labs between which they were transported and only our PI
was allowed to transport these from one place to the other.
5. Disposal of waste
All wastes need to be sterilized with proper treatment. Any container that has been exposed to bacteria cannot
be released until they have been exposed to high temperature and high pressure sterilization.
6. Other Daily Rules
◊ We are required to wear gloves, masks and lab coats before we enter the lab.
◊ Every time after finishing experiments, we should immediately wash hands with hand sanitizer.
◊ It is prohibited to bring foods or drinks into the lab or bring anything in the lab out.
◊ Periodically test and maintain the safety equipment such as fire extinguishers and emergency
eyewash in the lab.
Laws and Policies
Regulations of the People 's Republic of China on National Genetic Engineering Safety Management
Regulations on Safety Management of Laboratory in South China University of Technology
General biosafety standard for microbiological and biomedical laboratories People's Republic of China Health Industry Standard (WS 233-2002)