A variety of approaches to assessment of cellular integrity exist, based on tests of integrity of the plasma membrane, tests of metabolic competence, and asessment of morphology. By definition, such approaches address different aspects of cellular integrity and hence are not interchangeable indices of cellular integrity. Accordingly, it would be most appropriate to characterise hepatocyte preparations on the basis of more than just trypan blue dye exclusion (a test of plasma membrane integrity) as is customary. A scheme for the choice of the most appropriate mix of tests of cellular integrity is presented.