In our project we focus on using sRNAs in order to regulate expression of other genes. Our model is based on natural sRNAs from E. coli K-12, a non-pathogenic strain of E. coli. The strains we are using (W3110, DH5alpha and NM522) do not possess any of the known virulence factors of pathogenic derivatives of E. coli such as LEE or stx[1]. Furthermore, laboratory strains of E. coli would have difficulty competing for a niche in their natural environment (e.g. human gastrointestinal tract) as their metabolism is compromised in comparison to wild type E. coli. sRNA have not been implicated in virulence of E. coli until now and have only been been suggested to participate in the regulation of virulence factors for other pathogenic gram negative species such as Salmonella. Our model sRNA regulates uptake of a complex sugar and there is no mention in the literature of any link between this system and virulence, furthermore, bioinformatic data-mining on available DNA databases do not seem to suggest that this system could regulate any know virulence system from pathogenic bacteria. In order to prevent release of genetically modified organism to the nature, all the liquid waste containing GMO was sterilized before throwing away and all solid materials containing GMO were sent to incineration. Moreover this procedure eliminates a possibility of spreading antibiotic resistance genes used as selection markers in experiments to wild type bacteria through lateral gene transfer.

In terms of chemical safety we used only one potentially dangerous substance. That was ethidium bromide, which is a known carcinogen. For safety reason the main stock of ethidium bromide powder was kept locked and could be accessed only by highly trained laboratory technicians. The stock of ethidium bromide that we had access to was diluted to the level at which only chronic exposure pose a threat to health. This was however prevented by using gloves and following the protocol about handling this compound.

There is a set of chemical and biological safety rules that everyone employed or conducting a project at “Center for Systems Microbiology, DTU” has to follow. Before we entered the lab during summer we had to read this document[2] and participated in a three-day workshop. Then we were trained how to conduct experiments and behave in the lab in accordance to all safety requirements. We presented our project idea to one of the biosafety inspectors that works in the Center and discussed possible threats that might arise when using genetically modified E. coli strains. We concluded that as long as we follow standard safety protocols according to which research at the Department of Systems Biology is done, our project poses no danger. Rules that we were following during the scope of the project are based on Danish legislation[3] that was created in accordance to European Union directives regarding genetically modified organisms.


[1] D. Law, Journal of applied microbiology. 88, 729-45 (May 2000)

[2] Safety rules for Center for Systems Microbiology - 2011, Technical University of Denmark

[3] Bekendtgorelse om genteknologi og arbejdsmiljo - Sorry, the document only exists in Danish, "The Danish Working Environment Authority" describing regulations for working with gene technology.