isolating C. elegans from soil

[dave]

>CGC Bibliography Paper 1746
>
>A soil toxicity test using the nematode Caenorhabditis elegans and an
>effective method of recovery.
>
>Donkin SG;Dusenbery DB
>
>    Citation: Archives of Environmental Contamination and Toxicology 25:
>             145-151  1993
>       Type: ARTICLE
>      Genes:
>   Abstract: A new method for recovering nematodes from soils in an
>             efficient, reproducible, and non-destructive manner has been
>             developed. It was used to conduct short-term soil toxicity tests
>             using the soil-dwelling nematode Caenorhabditis elegans and
>             several different soil types spiked with copper chloride. The
>             recovery method, which involves centrifugation through a
>             colloidal silica suspension, allows the nematodes to be
>             extracted from the soil matrix so that lethality can be
>             assessed. The nematodes are unharmed by the recovery procedure,
>             and both live and dead individuals are recovered with high
>             efficiency (well over 80%), allowing reproducible
>             concentration-response curves to be made after a 24-h exposure.
>             The LC50s for copper were increased about tenfold by the
>             presence of soil, and different soils had significantly
>             different effects on toxicity. Toxicity of copper ion was also
>             influenced by the concentration of sodium chloride and potassium
>             chloride in the test solution, and the presence of bacteria
>             increased the toxicity of copper ion in some soils. The LC50s in
>             soil were close to the LC50 for the 2-week earthworm soil
>             toxicity test, suggesting that a 24-h nematode toxicity test may
>             be comparable to the 2-week earthworm test in terms of
>             sensitivity.



Does anyone have more informationg on this technique?