Safety
Overview
Synthetic biology is a powerful tool with the potential to respond to major challenges in modern society. However, it is also a double-edged sword. Because an ill-conceived or poorly managed synthetic biology project can cause great injury, any synthetic biology research or undertaking must be guided by biosafety and laboratory safety considerations. The NWU-CHINA-A team knows the importance of safety for people and the environment when working in a laboratory. We also understand the risks of working in the laboratory and promise to take all necessary precautions to ensure that no harm will be caused to individuals or the environment.
Secure Project Design
The strains we used in the project are Escherichia coli DH5α, Escherichia coli BL21 and Escherichia coli Nissle 1917 ( EcN ). Escherichia coli DH5α is widely used in genetic engineering and is classified as Biosafety Level 1 ( BSL-1 ). It already exists in the natural environment and can avoid the risk of species invasion. Under our experimental conditions, it is harmless to humans. According to the definition of German Collection of microbiology and Cell Cultures GmbH, it and E.coli BL21 were defined as Risk 1 Group with lower potential risk. In addition, the E.coli Nissle 1917 ( EcN ) we selected is a gene-treatable probiotic with a good human safety record and is becoming the most popular universal chassis for the development of intelligent microorganisms. [1]
We selected the suicide switch designed by Team:BNU-China/Design - 2019.igem.org. The suicide switch consists of a protein synthesis inhibitor ( RelE ) and an antitoxin ( RelB ). Among them, the translation of RelE gene is promoted by conventional RBS, while the translation of RelB gene is promoted by temperature-sensitive RBS. The expression of RelB is completed only when the temperature reaches the body temperature. Therefore, when the engineered bacteria leave the human body, the temperature decreases, the expression of the antitoxin RelB is inhibited, and the bacteria die due to excessive toxin RelE, which can prevent the leakage of strains and genes and ensure system efficiency and biosafety.
Fig.1 - Suicide switch diagram
In our wet laboratory, all upstream genetic engineering operations, such as transformation, vector expression, and protein measurement, are strictly followed and supervised by teachers or graduate students. At the same time, considering the risk of bacterial escape, all of our engineered bacteria are killed by 75 % alcohol.
Laboratory work safety
In the course of the experiment, we also attach great importance to safety issues. To this end, we implemented the following security procedures.
Personal protection
Fig.2-Wearing experimental clothing masks, wearing latex gloves for experimental operations and ultra-clean bench operations.
Safety equipment
Clearly place fire extinguishers, eye washers and other emergency equipment, including fire blankets, fire extinguishers and emergency buttons. Warning signs should be provided for dangerous places, equipment, facilities, articles and technical operations.
Fig.3 - Fire extinguishers Fig.4 - Biological safety cabinet
Chemical Safety
The location and proper storage methods of different types of chemicals in ventilation cabinets, combustible cabinets and general chemical storage cabinets should be marked with warning signs for hazardous chemicals.
Fig.5-Chemical special container
Building safety
Familiar with the escape hatch and emergency evacuation methods in emergency situations, keep the fire channel clear, and use safety protection facilities and equipment normally.
Waste treatment
Biosafety hazardous waste container
Fig.6 - Sharp waste treatment containers Fig.7-Medical waste bins
Safe Lab Work
Before starting work in the laboratory, all team members working in the laboratory must complete the complete training of molecular biology experiments under the guidance of laboratory staff and teachers. These courses have set up specific guidelines, which are the standard requirements for the first-class laboratory work in Shaanxi, China.
We also carried out laboratory safety publicity activities. Team members who knew laboratory safety skills well explained the rules related to laboratory safety to new students, which can not only make more freshmen familiar with laboratory safety but also make the laboratory safety awareness deeply rooted in their hearts.
At the same time, we have drew up a number of relevant safety rules. Team members who violate safety rules must work under the supervision of the lab staff until the lab staff believes that the team members are capable of performing tasks without supervision. In cases of repeated violations or complete non-compliance with safety regulations, members are restricted to laboratory work until they are retrained and show full compliance with safety regulations to the test staff.
Fig.8-Team members learn laboratory safety knowledge and safety procedures.
References :
[1]P. J L,Lisa G,F. C L. Emerging strategies for engineering Escherichia coli Nissle 1917-based therapeutics[J]. Trends in Pharmacological Sciences,2022,43(9).