Monday, November 7, 2016

Ames Test


The Ames test was created in the 1970s by a man name Bruce Ames.  The Ames test is a method to figure out if any chemical is a mutagen. This can be a pesticide, food additive, etc.  This also means that it can be a potential carcinogen.  In fact, if a chemical is a mutagen its chances of being a carcinogen are actually quiet high.  One of the bigger benefits of the Ames test is that is relatively easy, low cost, and quick to come to results.  A strain of salmonella is used to perform the test.  The strain of bacteria already has a mutation in its DNA.  Essentially these bacteria do not survive if you do not provide them with a certain enzyme.  The organisms are not capable of creating the enzyme as they normally would.  So the next step is you interact a chemical with these bacteria.  You do not provide the enzyme essential for them to live.  So if you add this chemical to the organism, and it lives, that means that the bacteria actually mutated to survive.  In other words, that chemical is considered a mutagen because the only reason the bacteria lived is because it mutated. 
Now this does seem a little counterintuitive, being that the most obvious mutation is actually just being alive.  So after Ames found this out, we started to test food additives.  We discovered around half of all food additives at the time were mutagens.  Now Ames being the great scientist he is said we need to also test all natural foods.  And in some cases we found that these natural foods had more carcinogens that the unnatural ones.  However these carcinogens are far milder, mostly negligible.   Were as unnatural foods often had lower amounts of mutagens, but they were much more potent. Ames explained this essential by siting the survival of the fittest theory.  Meaning the plants that survived, and were not eaten by insects, were likely to have higher mutagens.  These natural mutagens for example are produced in some cases to kill an insect that may be the thing eating the plant.  Again, this sounds pretty counterintuitive, but this by no means is to say that natural foods are less healthy than their pesticide sprayed counterparts.  So why are mutagens often carcinogens.  Well if you know anything about cancer you know that it is result of a mutated cell reproducing.  Essentially spreading the cancer or growing the tumor the cell may be a part of.  So some mutagens can cause this down the line.  In this scenario we consider them a carcinogen, or any chemical that causes cancer.  Just recently we even listed processed meat, as a carcinogen.  In fact there are carcinogens all around us we may not be aware of.  Many cleaning products for example contain carcinogens, but often times there effects are negligible.  This can either be because they are just not very potent, or because they are not usually ingested by humans.  Overall the Ames test has revolutionized the way we look at mutagens in our everyday lives.  It has supplied us with a huge amount of knowledge concerning the world in which we live everyday.