General Lab Safety

We followed all the basic regulations for any potentially dangerous experiments carried out in our lab. No one worked alone in the lab. All team members were aware of the purpose of each step of the experiment and of the potentially dangerous steps. Care was taken when handling live organisms and hazardous substances, and a particular care was given to the handling of toluene (see below).
Team members were required to wear appropriate clothing, lab coats, and gloves at all times when working. Safety gloves were worn before handling hot glassware.
At the end of the day, the last two people to leave the lab cleaned it and made sure that all of the machines and electricity were switched off, and that the incubators, the hazardous chemicals closet, and lab were locked before leaving.

Hazardous Substance handling

In our project we worked with some hazardous substances. Those hazardous substances were handled using every cautions described in their Safety Data Sheets.

First of all, GelRed DNA Stain was used to visualize DNA. Even if this substance was found to be non-cytotoxic and non-mutagenic at concentrations well above the working concentrations used in gel staining and test results confirm that the dyes do not penetrate latex gloves or cell membranes, we used the same precautions as for ethidium bromide. It was confined to a specific area of the lab dedicated to electrophoresis. The GelRed stain was manipulated using dedicated micropipettes and tips. (Please find GelRED MSDS here)

UV light was used to visualize DNA. To switch on the UV we had to put on protective mask to protect our eyes, as well as a lab coat and gloves to prevent skin exposure. Only the person wearing the UV mask could observe the electrophoresis results. Pictures were taken through a specific box with a hole for the camera in it.

Handling toluene

Of all the BTEX compounds to which our XylR protein is sensitive, toluene is among the most commonly used and the least dangerous. Here we present the basic information on toluene, important when handling it. (please find its MSDS here)

Toluene should be handled under a chemical hood by a trained scientist wearing gloves and a lab coat to avoid any skin contact. Do not breathe any toluene vapors. Toluene should be kept away from all heat sources, hot surfaces, and sparks as it is extremely inflammable.
Pure toluene was stored in a air-tight bottle with a special membrane to avoid toluene vapor emissions. A series of stock solutions (1g/L, 100mg/L and 100µg /L) were made at the beginning of work so that the pure toluene solution would not have to be used often.

Toluene was disposed of in a special container for inflammable substances. This container was then given to a company in charge of chemical waste disposal. After each use our toluene solutions (pure solution and dilutions) were stored in a cool, dry, well ventilated closet. The bottles were closed hermetically and stored vertically.

Concerning organism manipulation

Our lab is Level 1 with a laminar flow hood which allows us to handle Risk Group 1 organisms. Our project only involved Risk group 1 organisms and strains. ( E.coli DH5α and E.coli BL21). Living organisms were always handled under the laminar flow hood to avoid contamination or dissemination. Contaminated materials and work areas were washed with bleach, or ethanol.