For optimal cell growth, a constant temperature of 370C and 5–10% CO2 is required for incubators to maintained physiological pH (usually pH 7.2–7.4). 

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The carcinogenic effects of ionizing radiation and oxidizing agents are partly caused by free radicals that convert guanine to oxoG.

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#Id: 3267

#Unit 3. Fundamental Processes

Bruce Ames of the University of California at Berkeley devised a simple test for the potential carcinogenic effects of chemicals based on their capacity to cause mutations in the bacterium Salmonella typhimurium.

TLS Online TPP Program

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#Unit 3. Fundamental Processes

The Ames test uses a strain of S. typhimurium that is mutant for the operon responsible for the biosynthesis of the amino acid histidine. For example, the mutant operon might contain a missense or a frameshift mutation in one of the genes for histidine biosynthesis.

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#Unit 3. Fundamental Processes

Chemicals that are found to be mutagenic in the Ames test can then be tested for their potential carcinogenic effects in animals.

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#Unit 3. Fundamental Processes

Mismatch Repair Correction of the rare mismatches left after replication in E. coli improves the overall fidelity of replication by an additional factor of 10^2 to 10^3.

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#Unit 3. Fundamental Processes

The mismatch repair system of E. coli includes at least 12 protein components (Table) that function either in strand discrimination or in the repair process itself.