ABSTRACT
Twenty-five years have elapsed since one of us prepared this chapter for the first edition [1]. The book has been very successful, and the original chapter has been revised three times since then [2-4]. Many things have changed since the first version. Toxicology has become a more mechanistic field. In this fifth edition, the general discussion has been extensively modified. An additional author has been included to help with coverage of some of the areas. Some of the basic methods have been retained, because they are still utilized widely, without extensive changes, or they serve as prototypes for other assays. Several of the procedures have been changed in this fifth version to reflect perceived needs in readers’ laboratories. In some cases, detailed protocols have been deleted because commercial manufacturers routinely supply detailed instructions; in those cases some general guidance about the basis of the system will be provided. We will also refer readers to some details previously covered in earlier editions of the chapter and book.
