mini ames test

Image representative of miniAmes test (yellow indicates the positive and blue negative)

Key Features of Our Ames Tests

  • Reproducible and Consistent data

  • Rapid turnaround time (10 business days)

  • Best prices guarantee

The Ames test is designed to evaluate the potential of a test compound to induce reverse mutations in bacteria and is often used as one of the initial screens for potential drugs to weed out possible carcinogens. The Ames test is required for FDA IND submission. The tester Salmonella typhimurium strains e.g.TA100 and TA98 have point mutations while TA-1537 has frameshift in the genes required to synthesize histidine that make them incapable of growing in the absence of histidine. Treatment with a genotoxic chemical causes mutagenesis including base substitutions or frameshift within the His gene may cause a reversion to histidine prototrophy, and the mutated organisms are able to grow in histidine absent medium. 

Ames Tests Procedure

Image representative of mini Ames test (yellow indicates the positive and blue negative)

  • The Ames MPF test (mini Ames) use two strains TA98 and TA100, and the Ames OECD 471 test use 5 strains including TA98, TA100, YA1535, TA1537 and WP2 uvrA. 

  • Each strain is incubated with several dose levels of test compounds for two days in the presence and absence of S9 metabolic activation system.

  • If the chemical can induce mutagenesis then the mutated organisms are able to grow in histidine-deficient medium, and the indicator color will turn to yellow, while the negative show a blue color. A positive outcome is characterized by a dose-dependent increase in revertant frequency that exceeds strain-specific limits.

AMES II TEST

Ames II MPFTM 98/Mix assay allows a significant reduction of the quantity of test substance needed (50 mg) but remains applicable to the Salmonella strains used in regulatory protocol. High sensitivity and excellent correlation with agar plate test. High throughput, automatable for large numbers of compounds screening.

Key Features of Ames II Tests

  • Reproducible and Consistent data

  • Rapid turnaround time (10 business days)

  • Best prices guarantee

The Ames test is designed to evaluate the potential of a test compound to induce reverse mutations in bacteria and is often used as one of the initial screens for potential drugs to weed out possible carcinogens. The Ames test is required for FDA IND submission. The tester Salmonella typhimurium strains e.g. TAMix and TA98 have point mutations while TA-1537 has frameshift in the genes required to synthesize histidine that make them incapable of growing in the absence of histidine. Treatment with a genotoxic chemical causes mutagenesis including base substitutions or frameshift within the His gene may cause a reversion to histidine prototrophy, and the mutated organisms are able to grow in histidine absent medium. 

Ames II Tests Procedure

  • The Ames MPF test (mini Ames) use two strains TA98 and TAMix (TAMix contains: TA7001, TA7002, TA7003, TA7004, TA7005 and TA7006), and the Ames OECD 471 test use 5 strains including TA98, TA100, YA1535, TA1537 and WP2 uvrA. 

  • Ames MPFTM Penta: We test 5 strains, including Strains: S. typhimurium TA98, TA100, TA1535, TA1537 and E. coli WP2 uvrA + E. coli WP2 [pKM101]

  • Each strain is incubated with several dose levels of test compounds for two days in the presence and absence of S9 metabolic activation system.

  • If the chemical can induce mutagenesis then the mutated organisms are able to grow in histidine-deficient medium, and the indicator color will turn to yellow, while the negative show a blue color. A positive outcome is characterized by a dose-dependent increase in revertant frequency that exceeds strain-specific limits.

The traditional Ames plate incorporation test is one of the most commonly performed safety assays in the world, forming an important component of many regulatory submissions. However, with the increasing number of chemicals flowing through the drug development process, and the increasing demand for early indications of mutation and potential carcinogenesis, the number of Ames screening assays required is growing year by year. The traditional full-format Ames test cannot currently serve this market, since it requires too much chemical, labor and time to serve as a screening tool.

Principle of the Ames II Mutagenicity Assay The traditional Ames plate incorporation test is the most generally used and validated bacterial reverse-mutation test. The test employs several mutant strains of Salmonella typhimurium, carrying mutations in the operon coding for histidine biosynthesis. When these bacteria are exposed to mutagenic agents, under certain conditions reverse mutation from histidine auxotrophy to histidine prototrophy occurs. The increasing number of compounds to be screened and the fact, that new compounds are produced only in very small scale at this stage, were among the reasons to develop an alternative screening test to the traditional Ames test. The Ames II Mutagenicity Assay, based on the same principle as the traditional test, sets a new standard for this type of testing, offering several advantages over the traditional Ames test. The Ames II Mutagenicity Assay, available through $QLDUD, is a liquid microplate modification of the Ames test which offers a higher speed format, new strains, colorimetry, easy handling and the possibility of automated plating and plate reading. The assay is fast and efficient, consumes a lower amount of test chemical, shows good correlation with the traditional assay and was developed in the Bruce Ames laboratory at U.C. Berkeley (1). Due to the possibility of automatization, hundreds of substances can be run within a month. S

Strains used in the Ames II Mutagenicity Assay The two strains provided in the Ames II test kit are the Ames II TAMix and TA98. The Ames II TAMix contains an equimolar mixture of the Ames II TA7001-TA7006 strains. Like the traditional strains, the genetic background of the TA700X series strains have been modified to improve the sensitivity of their reversion. Individually, these strains are designed to revert by only one specific base-pair substitution out of all possible changes. Thus, when mixed, all base pair substitution mutations can be represented in one culture. The TA98 strain is used for the detection of frameshift mutations (1).

full ames test

The Full Ames test consists of a preliminary dose range-finding phase and the final mutagenicity phase. For the dose range-finding phase each strain, with and without S9, is plated onto a single plate with nine to ten concentrations of test material.

Typically, four tester strains of Salmonella typhimurium (TA98, TA100, TA1535, and TA1537) and one strain of Escherichia coli (WP2uvrA) are used in each assay

  • Others are available, including TA97a, TA102, and WP2uvrA (pKM101)

  • Each tester strain is incubated for 2-3 days with several dose levels of the test compound in the presence and absence of metabolic activation (S9)

  • Positive outcome is characterized by a dose-dependent increase in revertant frequency that exceeds strain-specific limits