Principles of animal use for gerontological research

This essay presents some practical advice and suggestions for those who wis h to use mice and rats in experiments on the biology of aging. Ten principl es set forth guidance on choice of ages, choice of stocks, the importance o f specific pathogen-free status, the uses of necropsy data, the dangers of pooling samples from different individuals, planning ahead for loss of aged mice to death and disease, the use of cost-adjusted power calculations, an d the dangers of inferring causal associations from correlated age effects.