Growth factors toxicity testing

Rapid and accurate assessment of viable cell number is an important requirement in many experimental situations involving animal cell culture, e.g. measurement of growth factor activity, serum batch testing and toxicity assays. 

Daphnids (water fleas) occur ubiquitously in aquatic ecosystems and, as primary consumers, they form an important link in aquatic foodwebs. The standard species Daphnia magna, which can be cultured in the laboratory, is used in toxicity tests to record adverse effects on the survival (acute, 48 h tests) or the growth and reproduction (chronic, 21 d tests) of the animals. The toxicity is generally described in terms of the EC5Q (EC effective concentration) that is, the level of the toxicant (mg/1) which affects 50% of the individuals exposed, regardless of how the effects are evoked. A variety of factors may considerably influence the absolute values of the observed toxic concentrations ... 

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