If you have worked in a science laboratory before, you probably know that contaminants are everywhere, whether you are in a chemistry or biology lab. Therefore, you can't have open food, drink or even lip balm in the lab.
Tie back any long hair that could fall into a cell culture or Bunsen burner flame. Wear closed-toe shoes so that spills fall onto the shoe and not your skin. Wear any protective gear you are issued, including goggles, lab coat and gloves.
Furthermore, if your immune system is compromised, talk with the person in charge of the lab.
Cell cultures look similar, so be sure to label them properly in case of spill or mix-up. If your culture is in a tube, even if the tube fully seals, be sure to store it upright in a rack. If you lay the tube on its side, it may roll off of the lab bench onto the floor and break.
For a culture plated out on a Petri dish, label the bottom part of the plate containing the culture, not the lid.
Before starting your lab work, and just prior to leaving the lab, wash your hands thoroughly with the disinfectant soap provided. At the end of your workday, your workstation should also be wiped down with disinfectant.
If there are any culture spills, thoroughly douse them with disinfectant, then report the spill to the person in charge of the lab.
Be sure to dispose of glassware, culture waste and chemical waste in appropriately labeled receptacles, not into the sink.
When using the Bunsen burner, be sure that it is supervised at all times when the flame is on. Before you set your inoculating loop down on the lab bench, run it through the flame of the Bunsen burner until it is red-hot. And prior to leaving the lab for the day, double-check that the flame is off and that the handle for the gas outlet is in the off position.