Re: cell cultures diffrent varieties their validity in the use as alternatives

This is an extremely broad question. In fact, the term "testing" could encompass many activities ranging from medical research to product safety testing. I am not sure in what part of this spectrum the poster is interested. However, yes, cell culture methods have been developed to substitute for animals in some cases. Refer to http://altweb.jhsph.edu for general information about alternatives, and a description of the three R's: refine, reduce, replace. A great deal of very specific information is available at http:// sis.nlm.nih.gov/altaniml.htm.

On the other hand, there are many situations, especially in the research arena, where there is no replacement for live animals. For instance, many diseases (Alzheimer's is a good example) are too complex to model in vitro, although the principle of refinement and reduction remains an important consideration. Additional examples are available at http://www.ampef.org/ and at http://www.fbresearch.org/ facts.html. I should also note that permitting use of human embryonic stem cells to grow complex tissues in culture is likely to lead (eventually) to reductions in animal use.

Let me encourage anyone interested in this issue to visit these sites. Unfortunately, there are many sites that distort the value of animal research by failing to acknowledge the tradeoffs that would ensue if such use was curtailed, and that propagate misinformation about the treatment of experimental animals.