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

  • Non-pathogenic strains

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]

  • Suicide switch

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

  • Safe experimental design

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

  • Experimental personnel should have a high sense of responsibility and a strong sense of safety. Theytrictly abide by the rules and regulations and operating procedures.
  • Emulsion gloves and safety glasses must be worn when dealing with infectious, toxic or hot items.
  • Smoking is strictly prohibited in the laboratory. Food, beverage and daily necessities shall not be brought into the laboratory. It is strictly prohibited to eat and drink in the laboratory.
  • Wash hands with disinfectant before leaving the laboratory. Close the hydropower switch and do a good job of safety inspection.

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

  • Biological waste (waste generated in laboratories should be classified according to the requirements and treated separately according to the regulations.)
  • Special container for chemicals 

Biosafety hazardous waste container

  • Sharp waste disposal 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).