Creating a sterile field is important in medicine and in science. The sterile field is an area with no native living cells. This includes aerobic and anaerobic bacteria, viruses, yeasts and mould. Sterility is difficult to maintain, but it is vital when studying the growth and mutation of any type of cell.
History of the Sterile Field
Ancient cultures used aseptic techniques to treat foods and wounds. While they may not have known why, many cultures washed and treated wounds with a variety of antiseptic treatments such as mercuric chloride. Before 1860, almost half of all surgical patients died from infection. Louis Pasteur showed how microorganisms affected food and created the sterile fields. At first doctors balked at the idea of washing hands between patients, but the practice soon became standard. The introduction of higher power microscopes, cellular dyes and stains gives researchers a better view of the cellular world.
Why Culture Cells
There are many reasons to culture cells. Some researchers culture cells to grow a sample large enough to study --- for example, if a student is looking at how many different types of bacteria exist on a comb. The student could easily look at the comb, but the bacterial colonies are too small to see clearly. While a comb is a minor issue, a doctor or diagnostician uses the same process to grow samples of unidentified bacteria in the bloodstream, urine or skin of a patient with a mysterious disease. Researchers also culture cells to see what effect, if any, light, chemicals or other microorganisms have on the cells.
The Importance of the Sterile Field
While the researcher works to determine the bacteria in a sample, it is vital that the researcher is sure he is only looking at sample bacteria. For example, a doctor may send a stool sample to the lab to look for fungal infection. Certain funguses indicate infection or inflammation. The researcher places the sample in the sterile media and watches for signs of any growth. If the media is sterile, then any fungal growth comes from the patient's digestive tract. However, if the media is contaminated by another sample, insecure handling or even bacteria from the air, the entire test is tainted. It may lead the doctor to a wrong diagnosis and even improper treatment.
How to Keep Media Sterile
Today, most sterile media is manufactured and sealed in a sterile environment. However, accidents happen. Before using any sterile media, the researcher must closely inspect the item. Each piece has an expiration date. Dispose of any expired media. Check the container for cracks or broken seals. Wash hands before handling the media or the sample. Wash the outside of both the media and sample containers. And use only sterile articles to move the sample into the media.
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