Microbiological tests Microtox

Microbiological tests such as the Microtox test report a non-quantal endpoint, which is an IC50. ECs are for quantal data (e.g., of immobilised daphnids). 

With the recent development of reliable microbiological tests for acute toxicity determination, such as the Microtox test (Bulich et al. 1981) and the resazurin test (Thomson etal. 1986), convenient tools became available for the investigation of larger series of chemicals in relatively short time and independent of local biological species and environments. It has also been demonstrated that these tests are generally quite representative of such... 

Microtox can be used effectively for screening of new water supplies, pre- and post-treatment monitoring to evaluate the effectiveness of such treatment and to test waters transported often for long distances under difficult situations to confirm that they remain contamination free. It should be noted that Microtox will detect chemical contamination but will not [Rovide information on microbiological quality unless significant quantities of microbial toxins have been released. 

In cases where it is acceptable to screen or monitor water samples by techniques such as the Microtox test, it would be prudent wherever possible to include other test methods. This would require the services of a reliable centralized chemical and microbiological laboratory suitably equipped with instruments such as atomic absorption spectrometers, gas chromatographs, etc. Tliese facilities would be used to check whether a water source is suitable for long-term use. 

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