Navigation Links
Ames test


The Ames test is a biological assay used in genetics, generally genetic toxicology , to test for mutagenic properties of a chemical compound. A compound is said to be mutagenic if it causes a change in the DNA (deoxyriboneucleic acid) of a living cell or organism. The test is named after its inventor, Bruce Ames.

General procedure

This assay is carried out using strains of bacteria, generally Escherichia coli or Salmonella that already have a single mutation, for example, a strain that cannot produce histidine, an amino acid that is essential for the bacterium to grow if not provided externally with essential nutrients. Cultures of the bacteria are grown in an agar containing dish so that a "lawn" of bacteria is present. The experimental cultures are exposed to the agent to be tested while the positive control cultures are exposed to a known mutagen to confirm that there has been no contamination of the strain. Strains of bacteria are available which have been genetically modified such that only a certain type of mutation (i.e. a base pair mutation or a frameshift mutation) will cause the strand to revert to a normal state, not requiring nutrients to grow. If the mutation screened for has in fact occurred dense spots in the colonies will form. A certain number of spots may form due to random mutation not caused by the agent; therefore, data analysis using control dishes is necessary. Occasionally a tested agent will be toxic enough to simply kill the bacterial culture in which case a "thin lawn" is observed.

S-9

In some Ames assays an S-9 mix is added. The S-9 mix contains liver enzymes, generally from a rat. These enzymes can metabolize the agent being tested in order to predict the mutagenic properties within a living system, specifically the source of the S-9 enzymes.

Mutagenic and carcinogenic correlation

Studies have shown that the majority of substances shown to be mutagenic by an Ames assay will be carcinogenic in humans.


'"/>


(Date:3/10/2015)... 10, 2015 Transforming How We ... "Personalized Medicine in Human Space Flight" by ... Goodwin , Ph.D. was recently featured by Springer Science ... years. Specifically, "Personalized Medicine in Human Space ... published in 2013 and 2014 from Springer in the ...
(Date:3/5/2015)... SAO PAULO , March 5, 2015 In ... with 41 percent of companies already using these solutions and ... of 2015. Of the latter, approximately 25 percent of the ... time. While the majority of companies in the ... is anticipated that the hybrid model will command significant attention ...
(Date:3/2/2015)... March 2, 2015 Synaptics Inc. (NASDAQ: ... human interface solutions, today announced a new implementation ... to enable rapid and secure transactions and reliable ... gaming is a turnkey solution providing mouse and ... quickly integrate fingerprint ID solutions into their product ...
Breaking Biology News(10 mins):"Personalized Medicine in Human Space Flight" Listed Among Most Influential Papers of 2013 and 2014 2Two of Every Three Brazilian Companies will have Invested in Cloud by 2015, Finds Frost & Sullivan 2Two of Every Three Brazilian Companies will have Invested in Cloud by 2015, Finds Frost & Sullivan 3Two of Every Three Brazilian Companies will have Invested in Cloud by 2015, Finds Frost & Sullivan 4Synaptics Unveils New Fingerprint ID Solution for Gamers 2Synaptics Unveils New Fingerprint ID Solution for Gamers 3
... risk of acquiring HIV rises during pregnancy, according to ... by researchers at the Johns Hopkins Bloomberg School of ... even after researchers controlled for behavior and other factors ... published in the September 30, 2005, edition of The ...
... trial, a new drug that selectively blocks immune ... kidney transplant rejection as cyclosporine, the standard anti-rejection ... drug, a co-stimulatory blocker called belatacept (LEA29Y), also ... the toxic side effects associated with standard anti-rejection ...
... have tracked down the biological trigger that gives ... bone disorder that can cause blindness and deafness. ... and could lead to new treatments for osteoporosis ... team from Lawrence Livermore and Lawrence Berkeley national ...
Cached Biology News:Pregnant women at higher risk for HIV, Uganda study finds 2New type of rejection blocker protects kidneys after transplant 2New type of rejection blocker protects kidneys after transplant 3New type of rejection blocker protects kidneys after transplant 4Researchers track down cause of a disfiguring bone disorder 2Researchers track down cause of a disfiguring bone disorder 3
Other biology definitionOther Tags