Intrinsic value and animal integrity are two key concepts in the debate on the ethics of the genetic engineering of laboratory animals. These concepts have, on the one hand, a theoretical origin and are, on the other hand, based on the moral beliefs of people not directly involved in the genetic modification of animals. This ‘external’ origin raises the question whether these concepts need to be adjusted or extended when confronted with the moral experiences and opinions of people directly involved (...) in the creation or use of transgenic laboratory animals. To answer this question, 35 persons from the practice of biomedical research who are directly involved in genetic engineering (scientists, biotechnicians, animal caretakers and laboratory animal scientists) were interviewed. They were asked to give their moral opinion on different aspects of the genetic engineering of animals and to react to statements about the concepts of intrinsic value and animal integrity. Analysis of the interviews showed that, contrary to what is often assumed, the respondents embraced these concepts, even those senses that (more) specifically apply to genetic engineering. And although the respondents raised some objections that go beyond issues of animal welfare, these objections could quite well be expressed in terms of the concepts of intrinsic value and animal integrity. In short, the results of the present study strongly suggest that these concepts do not have to be adjusted or extended in the light of the moral experiences and opinions from practice. (shrink)