Friday, November 25, 2011

Preparing Agar Plates/slants, Aseptic Technique

Preparing culture media

our first microbiology lab consisted of preparing slants and petri dishes in order to begin growing and cultivating bacteria. We prepared Agar slants and Agar plates which provide the nutritional requirements for cultivating bacteria.

During the lab we measures the correct amount of dehydrated media with water and adjust the ph to around 6.8. We then boiled the agar and poured the media into slants, and petri dishes. The slants and petri dishes needed to be sterilized in an autoclave. An autoclave creates a very high temperature steam which kills bacteria endospores. Other types of sterilizations include dry heating and filtration. Sterilization occurs at 160-180 degrees using dry heat. A filter is composed of tiny pores small enough to block bacteria and fungi, but not viruses. The autoclave seemed the most convenient at the time, plus our professor was really excited about using it!


Microscopic Aseptic technique

Aseptic technique is a useful procedure that is used continually in a microbiology lab. We had a chance to practice inoculating by transferring water from one test tube to the next. Aseptic technique is important because it is used to inoculate culture media with bacteria while avoiding contamination of microbes. After practicing aseptic technique we proceeded to collect an environmental sample of bacteria with using a swab. We figured that a lot of bacteria would be present on our foot stools and so we collected our sample from the railing of the lab stool. We streaked an agar plate with the environmental sample and placed it in an incubator at 37 degrees to allow bacteria growth.