Microbiotests - Model Protoxkit F -Ciliated Protozoan Toxicity Test

The chronic Tetrahymena thermophila toxicity test is a 24h bioassay based on the growth inhibition of the test organisms, with calculation of the 24h EC50.

• Tubes with ciliated protozoans in steady state condition, to supply the live biota directly for the Tetrahymena thermophila toxicity test.
• Concentrated toxicant dilution medium, tubes with substrate and reconstitution medium, spectrophotometric cells and cell holders.
• Short Bench Protocol and standard operating procedure brochure with easy-to-follow instructions and detailed illustrations.
• Data scoring sheets and a Quality Control specification sheet with batch number of the cysts and the media.

All test materials and equipment included in the Protoxkit F are available separately.

Reproducibility

• We produce high-quality uniform axenic stock cultures in strictly controlled conditions. This way, we preclude variability associated with recruitment/maintenance of live stocks in conventional bioassays.
• The quality of the standardised test medium is highly uniform, thanks to simple dilution of concentrated solutions of selected salts with deionised water.
• A Quality Control test with a reference chemical is described in detail, so you can easily check accuracy and reproducibility.

Cost-effectiveness

• The ciliated protozoans in steady state condition are directly available, which eliminates the need and the costs of continuous culturing and maintenance of your test organisms.
• The Tetrahymena thermophila toxicity test requires minimal space and equipment:
• spectrophotometer
• incubator
• conventional laboratory glassware
• If you store the stock culture properly, you can prolong the shelf life of the organisms for several months and reduce test scheduling constraints.

User-friendliness

• Simple handlings and scorings.
• Total performance time of the Protozoan toxicity assay is approximately 1 hour.
• We can provide you with a computer program for easy Toxkit data treatment.

Sensitivity

• The sensitivity of Tetrahymena thermophila is comparable to that of other ciliates in activated sludges and is hence a good indicator for toxic hazard in influents of wastewater treatment plants.
• Growth inhibition NOEC’s determined with Protoxkit F tests are ecologically meaningful thresholds for the protection of protozoan microfauna in benthic communities and the wellfunctioning of the ciliate component in activated sludges.

Validation