Within our laboratory all our tests are primarily done on in vitro cell culture. once we have shown activity in the in vitro assays and all other assays ie. solubility toxicity etc. we send it for animal testing. I work on drug discovery and this is the method we use. It will only be sent for animal model testing once it has been thoroughly tested in direct assays and in vitro cell culture. A lot of compounds are excluded in these phases that we would waste time on animal testing. however different methods for other areas of research are needed and it varies from lab to lab based on their preference.

I mean it is mandatory in regard of law. But for some test in vitro equivalents were developed during the last years and potentially this methods could replace the use of animals. But this is only for certain test like pyrogenic potential. I think you could test several things in cell or tissue cultures and hopefulle this replacements will be approved so that you don't need animals for  everything. However in some cases there will be not possibility to replace it

Sure we should try all we can to gain information before animal testing and develop better in vitro method to reduce testing animals used, but animal testing is still necessary for drug development. We saw a lot of cases where in vitro result didn't translate into in vivo result, due to many reasons. Take cancer as example, drug may not be able to penetrate well into bulk of tumor as cell culture, tumor microenvironment may contribute to efficacy or resistant, drug molecule may be absorbed by other normal tissues before they reach tumor, etc..  So it is not only a requirement by law, but also a necessary for developing a good drug. Likewise, animals are not human, no matter how much we do by cell cultures and animal models, we still need to run clinical trials on real human patients before a drug can be reliably used to treat patients.

@ Xin

my intention was not to say that animal testing is obsolete. I know and I support the use of animal models in case there is evidence gained by in vitro models and these result look promising.

But I don't understand why for example the REACH approach was started in europe to reevaluate the toxicity of substances. For many substance it is known and a lot of animals have to be sacrified for this purpous. Use of animals for drug development is needed but in some cases the use of alternative models could decrease the number of animals. And of course you can not translate the results from in vitro as well as in vivo approaches on humans completely.

Regards Sven

It depends on the study aim. in some studies you have to use in vitro model and some times in vivo. For example when you are studding signal transduction you should try cell culture and using animal models would be meaningless. in contrast, How can in vitro help you while you are doing developmental study!. 

Sure case by case, depending on purpose of the study and assay used, we should choose in vivo or in vitro models. In fact there are lots of efforts to develop in vitro assays to replace or reduce in vivo studies. E.g. to study the tumor microenvironment and cell-cell interactions, instead of animal or xenograft models, there are new techniques to make 3-D cell culture or co-culture models.  Not only due to ethical or animal protection consideration, but also these assays are much more cost-efficient. 

Hi Filippo, I understand why you may think that, but, while on this topic, despite the number of animals that are killed outside the lab, do we have the right to take advantage of the lives of animals within labs whatever the figures? I know it is for the good of science, but others may feel differently about this. What is your opinion? Do you think that because many animals die, because of human activity, of other causes, scientists should carry out tests on animals as they please? I think that using animals to test medical treatments is not always the most sustainable option, especially if there can be other ways of carrying out the tests.