Repeated blood collection in the laboratory mouse by tail incision--modification of an old technique.

Twenty years ago, tail incision for collecting serial blood samples from mice was introduced as a new technique. Despite a number of advantages over established methods, it has not become a frequently used technique. This report describes modifications of blood collection from mice by tail incision that allow obtaining rapid (1-1.5 min) serial blood samples (40-150 microliters) from unanaesthetized laboratory mice. Evaluation of corticosterone concentrations in the blood plasma from repeated samples indicated that subsequent samples were unaffected by the procedure. Furthermore, histopathological examination demonstrated that repeated bleeding did not cause any lasting harm to the animals. Blood collection by tail incision may, therefore, be of particular interest for studies that attempt to relate physiological measures to behavioral responses in laboratory mice, and may contribute to the refinement of animal experimentation according to the principles of the Three Rs.