Team:Technion HS Israel/safety

Technion 2015 HS Team's Wiki

Safety

What risks does our project pose at the laboratory stage? What actions are we taking to reduce those risks?
We work under Biosafety level 1 in order to protect others and ourselves from harm. First, we received training into laboratory safety from the lab supervisor that we are affiliated with, followed by good laboratory practice (GLP) and personal precautions. We ensured to protect ourselves and to prevent contamination of the cells we used by wearing lab coats and gloves .In addition we use special gloves and special goggles or helmets depending on which experiment we are doing.

How will our project work?
The work of our project is that genetically modified microorganisms can harm the environment if they spread in the wrong place and could cause damage to humans as well. Hence, in our project, we try to solve this problem by constructing a genetic circuit that is based on a mechanism that enables us to control the life span of bacteria and tie it to a specific environment to live in.

What risks might our project pose, if it was fully developed into a real product that real people could use? What future work might we do to reduce those risks?
Several risks/questions might be addressed: Firstly, what is the potential for gene transfer into unmodified organisms? Secondly , what are the risks of spontaneous mutations in the toxic gene to prevent death of the bacteria?

In order to address the first question we found the following information: Gene transfer depends on the ability of an organism (referred to as hosts) to take up DNA via conjugation. A recent publication by Caliando and Voigt (Nature Comm., 2015) introduced the idea of a CRISPR/Cas9-based degradation device that upon induction degrades targeted DNA. In principal, the adaption of this device and incorporation into our genetic circuit might prevent the risk posed in the first question.
The second question posed, concerns the mutation rate of lethal genes. In 1943, Luria and Delbrueck measured the rate of mutations in a kill switch from Knudsen and Karlstroem (1991). The authors grew cells (14 cycles of cell division), activated the toxic gene (relF) with IPTG and measured the survival of cells. The distribution of survival (shown as a poisson distribution) was shown to depend on the time of cell growth. Slowing down growth rates (reduced temperatures) and suboptimal growth medium (as used by us in the lab) might reduce the number of mutations in the toxic genes. Additionally, control of the expression of the protein might also decrease the rate for spontaneous mutations.

References

(1) Caliando, B. J. & Voigt, C. A. Targeted DNA degradation using a CRISPR device stably carried in the host genome. Nat. Commun. 6, 6989 (2015).
URL:
http://www.nature.com/ncomms/2015/150519/ncomms7989/full/ncomms7989.html

(2) Luria, S. E., and M. Delbrück. Mutations of bacteria from virus sensitivity to virus resistance. Genetics, 28: 491–511, (1943)
URL:
http://www.esp.org/foundations/genetics/classical/holdings/l/slmd-43.pdf

(3) Knudsen, S. M. & Karlström, O. H. Development of efficient suicide mechanisms for biological containment of bacteria. Appl. Environ. Microbiol. 57, 85–92 (1991).
URL:
http://aem.asm.org/content/57/1/85.long