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:11/21/2014)... November 18, 2014 According to ... by Systems (Video, RFID, Access Control, Intrusion Detection, Parking ... Banks, Government), Component Service Geography - Global Forecasts to ... is projected to be around $25 Billion in 2014 ... growing at a CAGR of 8.69%. Browse ...
(Date:11/21/2014)... Nov. 19, 2014  Earlier this year Donald ... College, and one of the most prolific inventors in ... are transmitted from Smartphones to third party agencies. Spector ... has one of the earliest known patents in this ... in the military, child care, elder care and hospital ...
(Date:11/21/2014)... VIEW, Calif. , Nov. 20, 2014 ... higher driver efficiency are piloting the North American and ... number of accidents growing, gesture recognition systems that are ... make a mark in the industry. ... the Automotive Gesture Recognition Market in Europe ...
Breaking Biology News(10 mins):Industrial Security Systems Market Worth $38 Billion by 2020 2Industrial Security Systems Market Worth $38 Billion by 2020 3Patented Biosensor Wearable Technology Provides a More Civilized Method of Quarantine 2Patented Biosensor Wearable Technology Provides a More Civilized Method of Quarantine 3Patented Biosensor Wearable Technology Provides a More Civilized Method of Quarantine 4Gesture Recognition Intensifies with the Rise of In-car Smartphone Integration, Says Frost & Sullivan 2Gesture Recognition Intensifies with the Rise of In-car Smartphone Integration, Says Frost & Sullivan 3Gesture Recognition Intensifies with the Rise of In-car Smartphone Integration, Says Frost & Sullivan 4
... CLEVELAND/ORLANDO University Hospitals Case Medical Center researchers ... a second chancejust not as they originally thought. ... harnessed from bone marrow that were believed to have ... if injected into the heart within two weeks of ...
... step closer to understanding what drives tumor metastasis, as ... can slow their own growth. In a recent ... the American Association for Cancer Research, Ral A. Ruggiero, ... medicine at the National Academy of Medicine in Buenos ...
... Findings from preclinical studies in a skin ... alone, or first-generation BRAF inhibitors used in combination ... have the potential to prevent drug-induced skin lesions ... The studies, presented at the AACR-NCI-EORTC International ...
Cached Biology News:Post heart attack recovery may not be aided by stem cell injections, but trial demonstrates promise 2New approaches may prevent certain side effects in BRAF mutation-positive melanoma 2
Other biology definitionOther Tags