Muta-ChromoPlate

The Muta-ChromoPlate is a 96-well microplate version of the salmonella typhimurium 'Ames Test,' used for detection of mutagenic activity.

Developed to test mutagenic materials in water soluble extracts of , sediment, air, chemicals, food components, cosmetics, waste waters, potable waters and any other material that can be solubilized or placed into micro suspension in water such that the material being tested can be taken up by the test strain.

The Muta-ChromoPlate provides a clear colour endpoint. Reagents, cultures and other consumable components are supplied ready-to-use in a non-specialized laboratory.

Principle

The Muta-ChromoPlate kit is based on the most generally used and validated bacterial reverse-mutation test, known as the 'Ames Test' (Ames et al., 1975, Mutation Research 31:347).

The test employs a mutant strain, or several strains, of Salmonella typhimurium, carrying mutation(s) in the operon coding for histidine biosynthesis. When these bacteria are exposed to mutagenic agents, under certain conditions, reverse mutation from amino acid (histidine) auxotrophy to prototrophy occurs.

Traditionally, reverse-mutation assays have been performed using agar plates. An alternate assay performed entirely in liquid culture is the 'Fluctuation Test' based on multiple yes/no colour endpoints (Hubbard, S.A et al., 1994, pp. 141-160, in Kilbey et al. (Eds.), Handbook of Mutagenicity Testing (2nd Ed,.) Elsevier Sciences, NY. This test principle is being applied in the Muta-ChromoPlate test kit.

Characteristics

The Muta-ChromoPlate Kit is generally more sensitive than the pour-plate assay, because it allows testing of higher concentrations of sample (up to 75% v/v). The assay procedure is simple and requires minimal training. Consumable components are provided with ready-to-use and step-by-step instructions. "Instructions for Use" are provided with the basic kit. The only equipment required are a 37 degree Celsius incubator and a single and a multi-channel micropipettor.

S9 and Activation of Pro-Mutagens

S9 is a crude liver enzyme extract that can, under certain conditions, convert materials without any genotoxic activity to active genotoxic entities. The chemical process involved is probably different for different materials. In addition, the lifetime of the activated moieties is extremely variable: some may be extremely short-lived. This is the reason for incubating the S-9 with the bacteria and the tested material at the same time.

Applications

*testing of industrial effluents for presence of possible mutagenic compounds

*screening of municipal discharges for possible routine presence or spills of mutagenic compounds

*screening of surface and/or groundwater for mutagenic residues

*Screening of potable water supplies for the presence of chemicals with mutagenic potential

*screening of water soluble air pollutants for mutagenic agents

*evaluation of pure or complexed raw mixtures for potential mutagenicity

*a convenient and easy to use teaching tool for university and college laboratories

Strains

Strains of bacteria which can be included in the tests kits are TA97a TA98 TA100 TA102 and TA1535

Colour endpoints of the Muta-ChromoPlate

Purple-non-mutagenic

Yellow-mutagenic

Capsule Story

Comparative sensitivities of the Fluctuation and the Pour-plate bioassays based on detection of minimum active concentrations (nmole/ml)

1) Bioassay results using strain S. typhimurium TA100.

2) Cytotoxic at this concentration

Plate 1 – Sterility control – all wells purple - sterility confirmed

Plates 2 – Background mutation rate determination. 17 wells yellow.

Plate 3 - Test sample mutation rate determination. 19 wells yellow – not significantly different than background. No detectable mutagenic effect

Plate 5 – Positive control – 96 wells yellow - strongly mutagenic

Environmental Bio-Detection Products Inc.

" measuring the health of our environment"

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